So the OP was hitching on the 12th but hasn't returned to tell us how easily it went, or didn't. LOL
Lnx, although on the face of it your information looks sound, it is in fact full of gaps.
You don't say how or where to hitch a lift with drivers using Eurotunnel or the Dover and Harwich crossings. Eurotunnel in particular is virtually inaccessible to hitchhikers at both ends. I can't think of anywhere near the Dover East terminal where you can hitch.
You don't say how people can get to Jabbeke Service Station on the E40 or to the toll booths on the French motorways.
If you're not in a car, you can't get into the Channel Tunnel to ask for a lift.
It doesn't matter how many free passengers can travel in a car or a lorry if you can't access the vehicles to ask for a lift. Many lorry drivers nowadays risk losing their jobs (i.e. their livelihood) if they gave a lift to someone going onto a ferry so they're not going to risk it. It was never easy hitching a lift with a lorry going onto a ferry: it's even harder now.

tony_b,
I have given a link to the hitchwiki page on the Channel Tunnel for reference. Hitchwiki also contains enough info about Dover, and anyone determined to hitch to the continent will find it there. Furthermore, there are good and bad spots mapped on the map there, and as far as I recall there is at least 1 good spot for hitching via Dover.
Jabbeke is easily google-able, and is mapped on most European road maps. Speaking of toll booths, I have only heard (as it says at the top, I have done some research but not yet hitched to the continent myself) that people hitch-hike there, and it's everyone's own business on how to get to them. Anyone adventurous enough to try to cross the La Manche for free will find a way to do it. I am sorry I cannot describe every possible route to every toll booth on every French Autoroute.
Regarding the last two paragraphs, it is true that you cannot travel through Eurotunnel on foot.
Hitchwiki lists Maidstone services as the best to ask for lifts, so if you really need more information, please follow the link.
Also, It is true that fewer lorry drivers would give you a lift these days, but it does not mean it's not worth trying.
I am sorry, but personally I am not entirely sure of the purpose of your reply - do you need more information (in which case please put a question mark after it, and someone will answer :)), or just want to criticize and discourage other people? Everyone can say and assume something is impossible, but only few will try to prove the contrary.
Kind Regards,
Lnx.

Lnx, I'm still waiting for the OP to return and tell us all how easy it was. But I have to note the OP is conspicuously absent so far.
That someone assumes something is impossible (which I don't think anyone has actually assumed), or that a few will try to prove the contrary, does not make the assumption false. But assuming it's doable is kind of like insisting if you hit your head against a brick wall often enough, the wall will fall down. Should I take it you buy a lot of lottery tickets too?
I think it is a fair assumption to make that if 1000 people start on either side of the channel with the idea of hitching a ride across, few if any will succeed. That 1 in the 1000 might is not proof that it's worth trying. It is in fact proof that it really isn't a practical solution to crossing the channel. That is what I think people are saying.
Lnx, I'm writing as one who has done a lot of hitchhiking around Europe in the past. It was always difficult to get lorry drivers to take you across the Channel for free. Yes, it could be done but it was time-consuming and you had to be very resourceful. A lot of cars crossing the Channel contained holiday-makers and all their luggage. Were they going to try to fit you in? Like hell they were.
Nowadays, things have changed dramatically. Motorways have been built that lead straight to the channel port leaving very few places to hitch a lift. Lorry drivers found carrying an illegal immigrant can be fined heavily and have their lorry confiscated. Company policies and insurance issues prevent lorry drivers from picking up hitchers. Hitchhiking is now far less common than before and hitchhikers are now often viewed with suspicion whereas before it was commonplace.
Hitchhiking in France was always notoriously hard, be that on the motorway system or non-motorways. Even an experienced, clean and tidy hitchhiker with a rucksack in dry weather could spend hours waiting for a lift. (I remember vividly spending a day-and-a-half trying to get out of Perpignan.) That's why hitchhiking organisations like Allostop thrived. Unfortunately, for a variety of reasons, hitchhikers in France are now faced with even longer waits than ever before. You advise people to hitch at toll booths near to the Channel ports. Great. Toll booths on French motorways can only be accessed from the motorways in a vehicle so you're faced with a circular argument. How do you get a lift to a toll booth near to a Channel port? That's what I mean by gaps in your information.
As for hitching at Belgian service areas such as Jabekke, the same issues arise as I set out in my second paragraph. It also assumes that people can get to Jabekke village in the first place in order to walk to the service area. Just because you can locate a place on a map doesn't make it easy to get to. Jabekke isn't the easiest place to get to - one look at the map will tell you that. It might be easy for a Flemish-speaking Belgian who knows the area well or can maybe take a short bus ride there. For a non-Belgian? Fill in that gap.
Trying to get across the Channel for free will mostly be very time-consuming. When you think that you can get a foot passenger ferry ticket for as little as £12/€15, it makes me wonder whether the effort is all a bit pointless.
You make it look like it's easy when it's not: that's why I took issue with you. Just because passengers can travel for 'free', that doesn't make it easy. All the theory in the world, all the out-of-date advice on the internet, won't make drivers stop for you when they don't want to or aren't allowed to pick you up. I'm not saying it's impossible. I am saying that it's much, much harder than you make it appear.

tony_b,
I shall comprehensively reply to your post as soon as I can (given that I have exams in a week's time) - all I can say for now is it took me 9 hours (2:22 initial wait) to hitch-hike from Maidstone Services to Delft, going via the tunnel in a car, and on the way back it took me 13 hours to hitch-hike from Hasselt (Limburg, Belgium) to Chesterfield, Derbyshire
(going in a lorry through the tunnel; Hasselt to Maidstone Services took 6 and a bit hours). Both times changing vehicles at Jabbeke.
The route which took 13 hours can be viewed here: [link|http://maps.google.co.uk/maps?f=d&hl=en&geocode=10650549355772091757,50.915460,5.324407%3B14495185541049141626,51.266341,0.614664%3B8768439401189258618,51.612880,-0.265270%3B6087437753830541084,51.607157,-0.274500&saddr=A13<i>%4050.915460,+5.324407&daddr=Unknown+road+%4051.266341,+0.614664+to:A5109%2FDean's+Ln+%4051.612880,+-0.265270+to:51.573656,-0.2314+to:Chesterfield,</i>Derbyshire&mra=dme&mrcr=1&mrsp=3&sz=12&via=1,3&doflg=ptm&sll=51.620148,-0.203247&sspn=0.148785,0.32135&ie=UTF8&ll=52.059246,1.549072&spn=4.715778,10.283203&z=7]
Lnx

I came across this thread through searching hitching stories on google.
I hope those that live in such constant fear are happy. To me, this is impossible, but miracles happen..a chicken may meow..
I hitchhike often to Paris from London. I can make the journey in about 8 hours, 4 to Calais.
The girl that began this thread? Never give into people like the above. Damn, no wonder England is falling apart, the grandchildren of grandchildren of blood thirsty colonialists..okay. gottit!
Last summer I hitched over 10,000km around europe. I met wonderful and great people telling amazing stories. Its the greatest way to live, for me.
#17. Instead of tub-thumping and bragging about your hitchhiking exploits, why don't you add something useful to this thread and explain in detail how you hitchhike from London - Paris?
Your description of English people couldn't be further from the reality. The blood thirsty colonialists stayed in the colonies, not in England, so it would be hard to live in England and be a descendant of those colonialists.
I'm not surprised at your failure in logical thinking though. Let us know when you hear a chicken meow and when you witness a miracle.

You didn't understand. I meant that living in fear must be so terrible and that to be happy and to live in fear simultaneously is as possible as chickens meowing. I'm looking forward to a chicken meowing but I doubt it'll happen.
My problem with English people, being English, is that so many are so fearful and paranoid of everything different. The media perpetuates this. Thats terrible. oh, a black person! oh no...its just my shadow...
Having said that, hitching in most parts of England is okay, the people who go against the stream are wonderful and have fantastic stories to tell.
To hitch from London to Paris, start from Mottingham at the petrol station just off the railway station which can be reached from London Bridge.
From there you can get to Dover quite easily, last time it took me around twenty minutes waiting for a ride to Canterbury and from there to Dover. At dover, around 5 minutes of waiting for a truck, which got me through to west of Paris. Wait at the roundabout, officials may stop you inside the terminal trying to hitch.
Use signs, Dover in London, Calais at Dover and Paris at Calais. Its helpful if you can get a ride past Calais from the ferry.
Coming from Calais to Dover, its easier if you can get dropped off at a Peage a little away from Calais if your ride isn't going the full distance. It took me 10 minutes waiting for a ride to Dover from about 60km from Calais.
Thankfully, most people who write on these forums don't go outside. One less car to go past us while waiting for a ride. :)