Tonight I tried Skype for the first time, and I’m impressed. It has excellent voice quality, using full-spectrum sound as opposed to the ~2.5KHz band of a normal telephone. We had a few drops but not any worse than my cell phone. If you can get used to talking to your computer instead of a phone handset, this can replace the phone for a lot of situations. Oh, and it’s free. As far as I can tell, though, Skype does not encrypt the voice channels so I wouldn’t use it for sensitive communications.