WireTap Studio is in its infancy at version 1.0.9, but already it's got some great potential, and is already quite useable for recording and edition a simple VO track.  I discovered it while taking a tour of the latest MacHeist bundle.
If you buy it in the next few days, you get WireTap Studio, a $69 application, for $39, and a SLEW of other applications as well. 
After playing with it for only 15 minutes, I can say it is a very well designed application and is highly intuitive to use.  It can record ANY source, including audio output from applications such as Skype, Firefox, or anything that creates sound.  It also can record from two sources simultaneously. 
Another innovative feature is the ability to preview in real-time any file format and audio codec settings so you know what the final product will sound like without needing to export and playback to test.  It's 100% non-destructive so your original uncompressed audio is always intact.
Definitely worth a demo!