We got two iPhone 3GS' in Aug 2009. Both phones work fine just that they are slow. I would like to get new phones but hate the fact that I have to throw these away. What have other people done ?
Call ATT and unlock them, then sell them or give them away to charity. I think there is some place where you can donate your smart phones for the soldiers overseas.
I would build something with them if you can. Use the display or connect the iphone via usb after "jailbreaking" it. I'm sure the wonderful people here can offer a multitude of suggestions.