Khema, sorry if I have posted some wrong information here, but I'm not encouraging people to travel to Tibet without TTB permit. What I told here are the stories told by other travellers (yes, western look) I met here in Lhasa who don't have permits and never got any problem, even after the EBC protest! Now usually if I meet any western travellers, one of the first things I asked them is permit, if you ask around, you'll know many people who actually don't have a permit and never have any problem.
I just have the impression that it's okay to travel without the entry permit. ALSO, it's okay for those without a TTB entry permit to join a tour from Lhasa, this is confirmed also after the EBC protest. (I met some who go to EBC without an TTB entry permit, but they have to join a tour and get an ATP permit from Lhasa.)
I guess the permit system isn't perfect, many people don't see the piece of paper at all, many people got no problem without a TTB permit.
(An ATP permit seems to be necessary however in some sensitive area. )
And about the train ticket, since the tickets aren't registered with any names, I don't see any reasons why you can't ask other Hong Kongers to buy one for you. I'll call to confirm again.
I just called the lady at the China Railway Office, Hung Hom, Hong Kong. She said they cannot sell tickets to foreigners because they will take responsibility if the passenger cannot take the train. But all tickets aren't registered by names or ID card or passport number.

to #11 pazu
I made that comment because in your earlier post here you said "but it is okay to take the train from Guangzhou to Lhasa without any permit, nobody checked, I took this line twice"
my point is that if you look Chinese (and not everyone here knows that) you may be have lower risk of being asked a permit while boarding the train
if many Westerners that you meet in Lhasa won't asked for permit on the train that's great, but there were probably some who were, and also there were some who could not go on tour outside Lhasa without the TTB permit. I'd like to make it clear to those who are thinking of visiting TAR that chances of getting caught are 50/50, and everyone understands the risk before they decide to forgo obtaining the permit.
Hi Khema,
Okay, I understand your point. I will ask more westerners about this information, if I meet another 30 or so westerners taking a train without a permit and never got caught, I will tell you guys not to buy ther permit for the train again.

there is a company (Chomolungma or maybe the tibetan spelling)
I got the number from the agency which is situated inside the Visa Office, wan Chai , china ressource building 7th floor,
They can give you a number or i can post it later (have to look it up again)
The agency also deliever the permits to Hong Kong.
maybe that helps with the ticket.
It cost a fee and needs 10 days.
This company, located at Jaffe Road, is 5 minutes away from my home. I went and asked them about the permit seven years ago and what I remembered was that they had some really expensive (ridiculously expensive!) tour. I'll give them a call tomorrow to see if they can do anything new to help other foreign travellers.
You'll see from my other posting that the Jaffe Road agency (I presume we're talking about the same place) told me on Friday that they will only give permits to people on guided tours and that they cannot get me a permit that will allow me to travel individually from Guangzhou. Things have tightened up after the recent EBC protest.