unlock your iphone using yellowsn0w.
get it in cydia. google for the instructions.

hi seniors,

i have very smart brain and i have accidentally updated my firmware to 2.2.1, meaning it's running at baseband of 2.30.3, which means i have screwed up, congratulate me.

since i do not know when the dev team will release the unlock for 2.30.3 baseband, i was thinking if i could use those sim unlocker, like a chip or something, some people said MINE IS WORKING PERFECTLY!! some say there is alot of problems and preferred unlocked phones, well i am actually very blur now and do not know whats going to happen if i use a sim unlocker too, this is my planning, use a sim unlocker first and wait for the unlock release, when its released unlock the phone and use back a normal digi sim card.

anyone can give me any suggestion or advise? whats gonna happen if i use a sim unlocker?

thanks in advance seniors.