While randomly browsing tonight I found FoxyTunes, which basically puts a connection to your music player (looks like pretty much any platform) controls into the firefox window. I'm not sure how useful this is in Real Life yet, but so far it's handy to be able to just mouse down to a play/pause/next/prev button instead of hitting the key on the keyboard, or going to a separate app. Similar to the WMP windows toolbar thingy.