If you know what Ultrasn0w is, then you maybe just did a little happy dance. If you don't: it unlocks your iPhone to work on other carriers. If you don't care for AT&T, for example, you can use Ultrasn0w on T-Mobile. One tip: you'll have to disable 3G for T-Mobilers in the US of A. Lucky us, eh? Ultrasn0w doesn't magically add CDMA powers to your iPhone, so give up your dreams, Sprint, Verizon and just-about-everyone-else-customers.