Splice is a flash-based online music maker, where you can use other peoples sounds, mix, remix, and record your own music, sounds, then publish to the site for everyone to hear. Social music making and sound sharing is fun and pretty cool too. I could see it used for podcasts or simple loop creation (depending on the quality) but I haven't tested it out yet. The site is flash based, so I imagine it can be used on Windows, Mac, and someday when Adobe gets with it and releases a flash player, Linux too. Splice is free to use on the web.
[Via LifeHacker]