For those with the iPhone 3G, what do you plan on doing with your old phone once you get the newest iPhone? Is anyone going to buy these on ebay/craigslist? It is not easy to unlock the 3G, so the demand will likely be low (unlike the orig iPhone)- no? It seems like the only market would be existing AT&T customers who don't want to lock into another 2 years, but want an iPhone. Thoughts?