Mobiles.co.uk - £20 up front for the phone. £30p/m including internet. Went through Fatcheese.co.uk and got £35cash back on purchase. Traded in old n95 8Gb through fonebank for £121.

I wanted to buy SIM free but it always came out cheaper on tarrif.

Went from 3(not bad but not that great either) to Voda and I've got to say, it's an improvement from 3. The 500meg limit is not that rigid and they don't mind you going over a bit. Coverage is very good overall.