if you decide to sell it on ebay, you'll probably get more for it if you part it out. At least, take out the hard drive and ram. If you are technically inclined (meaning, you have a very, very small screwdriver/torx set) do what was mentioned before and get the touchpad, keyboard.
Screens are getting good prices. Besides their original use, a lot of people are finding alternative uses for them, like DIY digital picture frames and mounting them in their "carputers."
If you can get at the CPU, it might be worth getting out if it's a pentium3/high-end celeron or pentium4. Whatever your CPU is, check the prices at ebay or other places and see what the used ones are selling for.
Also, make sure there is nothing on the hard drive that you don't want anyone else seeing. If you have sensitive stuff on there, you can get an adapter for about $5-7 that allows you to plug it into a PC mainboard and use it.
Copy anything you want to save, then do a low-level format(writes 0000's to the entire "usable space" on the drive) with the drive manufacturer's utility (Seagate, WD, IBM/Toshiba all provide their utility for download)
Another thing- save all the little screws that you took out and keep track of where you pulled them out. You could either sell those on their own, or you could include them with whatever they were holding in place.
I know from experience that whomever is on ebay desperately looking for a replacement touchpad is probably not thinking about the screw that used to be on the table, but has since rolled off, never to be seen again.