Changing IMEI Numbers

I am looking for some information regarding changing IMEI numbers on blocked phones.

Any information would be good, but blackberrys & iphones specifically, don't mention ZIPhone.

Thanks

I'll actually going to help you here, even though it isnt related towards programming, just because I was in this situation a few weeks ago.

I tried it for a blackberry 3g 9300 I found, but it wasnt recognised by the MFI multi-loader; thus it didn't work.

Follow this http://www.ipmart-forum.com/showthread.php?p=3285604

However, the much simpler option, which i'm going to do is sell it abroad via ebay or the likes because it's only blocked in your country (Im assuming UK because it cant be blocked in USA).