Whatever you do DON`T download an app called ICEY, it`s an alternative to cydia but it bricks your phone.
My phone was bricked by it last night, in the middle of fixing it now but i gotta update it to 4.3.5 firmware or apple refuse to restore it!
So now i gotta update and jailbreak using RedSnow.
What a bummer, more guttered over my tiny tower game
Gonna have to start all over again now