I'm looking to get an external CDR drive (preferably firewire, and even more preferably firewire & usb) and wanted to see if there was one made that gets its power over the interface cable and doesn't require an additional power supply.

Does anyone know of one? I'd prefer to get one of those sort that has a normal IDE drive inside it so I could swap it out for a hard drive on occasion, or just an external enclosure so I can definitely do that, but it's possible that only the small laptop-oriented ones will get power the way I want.