I own a Palm Treo 650 that I’m about to replace with a Blackberry, and I’d like to sell the Treo on ebay. I bought it new from a dealer (not from my cell provider), and it was unlocked for GSM systems (T-Mobile, Cingular, etc). I’ve used it for over a year now. Will I have to have it unlocked again for the next user, or can they just slip their SIM card into the phone and begin using it?

Cell Phone Magazine