On eBay it seems all 2g iPhones are unlocked, so if you unlock yours, right now you can get $400 or so. I was just looking at a few 8gb unlocked 2g iPhones and they are ending in a little bit, and they are all around $350 - $450. I don't know what the value would be later when/if a 32GB 3g comes out...should still be around $300 - $400.