Just got a new laptop with a built in 3G card – had been considering getting mobile broadband anyway. The thing is, I went and looked at the 3 website, and it's £10 a month for mobile broadband for 1GB. However it seems if you have a normal PAYG phone SIM card you can convert a top up to a month of unlimited internet for £5 (or alternatively have the internet for a day or a week, which would probably suit my sporadic usage). If I bought such a normal SIM card and put it in my laptop 3G card, why couldn't I use it? I'm sure there must be some catch that I'm missing, but I need it explaining to me.