So why didn't you ask what the rules are in Italy and Greece instead of UK and the EU?

I was hoping i could use a bike everywhere but those where the two main places i was thinking, and seeing i am going to be in many more places other than Italy and Greece i thought i better ask a broad question rather than asking about just two countries at a time.

Well I've already told you about Greece Gramsay.
"For example in Greece you need a license even to ride a 50cc scooter."
So you won't be riding there and a scooter is in fact perfect on the islands.
I take it you are not going till this summer some time. Why can't get get a license in Australia before then?
If you're going to tour europe by motorbike, you will need a motorcycle licence. You can get one in oz or reside in a european country for a while to get one. If you want to buy a bike, it makes things a lot easier to have an EU licence.
If you don't want to bugger around with getting a licence, you'll have to stick to renting 50cc bikes where you are allowed to. I'm sure it can be done in italy. In the UK you may need to sit a CBT to be allowed to ride a moped.
Riding on two wheels requires greater skill and awareness than in four, so you would be best getting some practice at home before risking your skin in a foreign country with different driving rules and habits.

Hold up your hand if you want to insure the OP to ride a scooter in Rome or Naples. What, no takers? LOL

I'll be going in our summer EU winter around the 26th november but i wouldn't be going to italy until the weather is a tad better otherwise i'll be in Austria and the UK soon after i get there until i want to go to other contries later in the year, i don't think it takes much to get a licence here i may do that if i can use it over there as well, would they take a Aussie DL or would i need an international DL
Austria in December on a small motorbike??? That's the time of year when motorbikes are put away in the garage until spring. Italy may be a bit better, as snow is less likely, but stillnot exaclty motorbike season.
I presume you will only go riding after Winter?
Do you want to tour all of europe or just hire a scooter here and there?
You could do a tour if you rented a bike, but renting a decent touring bike is more expensive than renting a car - often up to double the price (mostly for insurance reasons).
You could buy a bike in Europe, but you would need a permanent address and convert your licence to get an EU one so you can get insurance. And if you haven't had your full licence for very long you will pay through the nose for insurance.
I take it you're not really "in" to biking or you would have had a licence already, so a big tour may not be your thing? Imaging riding through driving cold european rain at 130km/h, soaked through and not being able to see anything through the visor. And you only have enough room to carry a toothbrush and a change of underwear.
Best bet is to get your licence in Australia, and hire smaller bikes/scooters for short trips around the place. 125cc is the smallest you should consider if you want to drive any sort of distance out through the countryside.
To get a licence usually you need to sit a Compulsory Basic Training course, and do a practical test at a later stage.

Yes the folly of the digital medium is that no matter how clear i think i have made myself someone will take it the wrong way, because i will be there (Uk and the EU countries) for a number of warm seasons i wasn't planning to ride during the bitter cold months or though countries that are normally cold in general my main plan was to ride out to some country area's in mainly italy/france/some UK and maybe a few other area's i've seen though if i can get buses and or trains to most of these places then a bike will be redundant, it does seem though for what i am thinking it may be possible for day trips with small cc bikes if i do find out that it's not then i will just have to find other ways to get to the places i might want to go to, just thought it might be nice to take a ride to some country areas that most tourists dont go to