browserTunes allows you to remotely control iTunes from any web browser. Just point the browser to http://yourmac:8080 (where "yourmac" is the name or IP address of your Mac) and you can play songs, pause, get information about the song playing, view and play playlists.
browserTunes works fine for PDA browsers and perhaps also with phone-based browsers.
So if you have an Airport Express in your living room and your computer with iTunes in the basement, you can control the music from a handheld browser.
