Andrew Kazmierski and Mark Davis released Musicast on Tuesday, a new application that allows users to share their iTunes playlists over the Internet. With Musicast you can broadcast select playlists and have them accessible to friends using a Web browser. According to the developers, Musicast will even tell you which of your friends are browsing and how popular each of your cast’s songs, artists, and playlists are. Musicast is requires Mac OS X 10.4 and costs $18. A demo is available that limits users to broadcast two shared playlists.