I'd just keep checking the Apple refurb page. The deals that plinden posted are pretty good. However, the 1.2 GHz iBook he posted has a plain CD-ROM drive which is pretty limiting. Keep checking and I bet a 1.2 GHz machine with a combo drive will come up for sale. It'll probably only be $749 or so, which is a really good deal IMO.
Refurbished units are a good deal because they come with the full Apple warranty, Tiger and iLife '05, and you're almost guaranteed that they are in excellent working order. There are a lot of people here on Macrumors that have refurb units, and I haven't come across anyone reporting a bad experience with them.