I was just checking the tariffs on O2 after my bill came through today, to see whether I should upgrade for unlimited texts. At the moment I'm on 'Online 20' - I pay 20 a month (SIM only) and I get 400 mins, 1000 texts and 1meg of data per month.

Pretty good, but if I upgrade to the 'Online 25' I move up to 600 mins plus one 'Bolt on' which can be Unlimited Data! For a total of 25 a month!

http://shop.o2.co.uk/tariffs/sim_only