This is such a fun site! You create a profile, upload up to 12 mp3s, make any editing you need to make, name your mix, and then tell your friends! It's not perfect: uploading is slow, it only accepts mp3s and even then it seemingly for no reason rejected a couple of the mp3s I tried to upload [perhaps an editorial statement?], but hey, it's free, and it's neat-o.
Here is my mix (or "mux", as the case may be).