Mixwit is a free web 2.0 application that allows you to make "Mix Tapes" using music from Skreemr and Seeqpod. You can then decorate the "tape" using the skins provided or by uploading a picture. These mixes can then be played from the Mixwit site or embedded into a blog or other website.
I think this will be a great application for my classroom. I can make mixes of my student's favorite (school appropriate) music, load it up and then put the mouse cursor on the "next song" arrow/button so that the student can cycle through the songs just by hitting her or his switch (thankfully it starts over at track one when you click through all the songs).
Here is a sample mixwit you can play right in my blog, I made it for my friend's five year old (who has been singing at open mics since she was three).