Help with unlocking my Iphone 4

[VO #23]

I've just moved overseas for a semester and want to unlock my Iphone 4. I've downloaded and run Cydia (it now appears on my phone as an app), and recently tried to put a new SIM card in it and it didn't work. Any thoughts on what I need to do next? I've checked out Google and YouTube fairly closely but can't find what I'm looking for (I might need to change an .ipsw file or something?) Any help would be greatly appreciated!

[Jimmy Stang]

Check this thread out. The people who frequent it were very helpful as I prepared to jailbreak/unlock my 3G.

http://forum.calgarypuck.com/showthread.php?t=91212

Although it may be a bit different for the 4, I basically did Redsn0w and then from Cydia, Ultrasn0w. I'm actually in the UK right now on holiday and I popped a Vodafone sim in there and I was good to go.

[VO #23]

Awesome, thank you! I searched for ultrasn0w and ran it - is there any way to check to see if it's unlocked now without using a SIM card? Like through settings or something?

I'm such a n00b

[Jimmy Stang]

Before I came over here, I borrowed a friends Bell sim (it was a Fido phone originally) and tested it out. Put the sim in and then call that number, and your phone should ring.

Not sure if you know anyone there with a sim that you can borrow to test it. I believe the iPhone 4 takes the little micro sim.

If all else fails, maybe someone at the phone shop can let you test it out before you buy a sim.