I have an unlocked AT&T iPhone 4 (unlocked two weeks ago), and a SoftBank iPhone 4 (obviously locked, and with the current baseband, cannot be unlocked). I used the latter to get me a USIM for the former. Works awesomely. Now, they scanned the IMEI barcode when they gave me the USIM.

Is that IMEI locked to me now? As in, if I try to sell the iPhone 4, and someone else gets service with it, will it come back to me or get denied for the person I sell the phone to because I am still using my own service? I can see plenty of reasons where I might need a spare phone, and I didn't pay all that much for it, so I am not opposed to keeping it, but I thought I should know my options...

I am currently in the process of doing both Resident and Non-Resident write ups about iPhones, considering how many questions there are constantly asked on this and other forums concerning them. It sure as heck would be nice if Softbank would follow AT&T's lead and start unlocking phones that have been paid off already...