YouTube is a great source of live music performances and other audio treasures. Music companies get upset that their tunes are used without permission in lip sync and other types of videos on the site. Where they see conflict, others see opportunity.
We've seen a number of new services lately that focus on the audio in YouTube videos, but the most enjoyable one so far is Mixtube - a mixtape maker for YouTube audio. It's based on the metaphor and interface of the now "sleeping" Muxtape.
The sound quality on YouTube is often not so hot but we appreciate the opportunity to do things like set up an auto-advancing playlist of Dar Williams live performances. There's all kinds of nice little interface touches here, making it a really easy site to use.
We expect the site will be operable indefinitely, as YouTube rarely comes down on derivative services. Thanks to Andy Baio for finding this one.