http://live.pirillo.com/ – Highspeedhomer asks “is there a good free audio mixing program?” There is, but it’s not free (it’s open source).

Audacity, the free, open source, Audio Mixer.

Audacity is a free, easy-to-use audio editor and recorder for Windows, Mac OS X, GNU/Linux, and other operating systems. You can use Audacity to:

• Record live audio.
• Convert tapes and records into digital recordings or CDs.
• Edit Ogg Vorbis, MP3, and WAV sound files.
• Cut, copy, splice, and mix sounds together.
• Change the speed or pitch of a recording.
• And more! See the complete list of features.

SoundForge Audio Studio offers similar functionality to Audacity, but it’s not free.

Sound Forge Audio Studio software is everything you need to produce professional-quality audio on your home computer. No more renting expensive studio time to get the results you want! Record just about anything, edit and restore audio, burn your own CDs, create streaming media, and convert files with lightning speed all using drag-and-drop actions and simple commands such as cut, copy, and paste.