We recently did some phone swappin' at my house, and this guy is no longer being used. It's an original 2G iPhone, jailbroken and unlocked, running iOS 3.1.3. It's still a very good phone but lacks the newest whiz-bang features of a 3GS or 4. It's also a great iPod Touch if you want to use it without the SIM card.
Sorry about the fleck of dust on the screen...
Back is pretty clean but has some scarring at the upper corners.
Cydia icon shows it's jailbroken.
This thing is bone stock and unmodified except for the installation of Cydia and the jailbreak. It should run on a number of carriers or with a pay-as-you-go SIM card but I only have AT&T here to test with so I can't really say.
Asking $150 shipped CONUS or $145 plus shipping for international. Not looking for any trades at this time, thanks.