Call Recording on Droid...?

I'm not sure about the apps, but you can use Google Voice to record phone calls as long as the person calls you. After you accept the call through your GV number, you hit "4" to start the recording. Its then saved as an .mp3.

Obviously this is not exclusively a Droid feature (or even a cell phone feature -- it'll work on any touchtone phone you use with GV), but it is a way to record calls.