We all did it. I know I did!! We took songs from different albums (and later DVDs) and put them on a cassette tape to listen to on long rides in the car, or better yet, give to friends.
Well now you can create your own virtual mixtapes online and share them with your friends!!
Just create an account, load up and organize your favorite songs. You can send the link to your friends, publish it on your website, it even gives you a RSS feed!!
Here is my muxtape: http://multimedialibrary.muxtape.com/