I ended up selling both my 32gb 3GS and my wife's old 16gb 3G on fleabay. Both were upgraded to 4.0 which I subsequently jailbroke with the latest redsn0w. I gave full disclosure in my ads that both were running iOS4 and were jailbroken, both sold within a couple of hours of posting. The 3G, I
THINK I was able to unlock using Cydia and repo666.ultrasn0w. The software showed it had been unlocked. I listed in the description exactly what I had done and that I was not entirely sure if it was truly unlocked or not since I didn't have another carrier's SIM to try in it. There are definitely buyers out there, I just like to use full disclosure