iPhone in UK/Europe

[alex571]

I'm an Australian and am planning on travelling through Europe and the UK later in the year. I'm wanting to pick up a pre paid sim card in the UK and use that for my trip. Preferably I would like to get one that allows for calls as well as data. I was just wondering if you guys could give me a few tips re which ones are best and also wether or not it is possible to use 3g data services throughout the rest of Europe without incurring extra roaming costs.