GoogleTube is a nifty little player for YouTube, accessible from the status bar and within Google, Yahoo! and Bing search results.
Think of it as a combination of a search and recommendation engine for music, live shows, movies trailers and more...
Search for bands or artists on allmusic, Amazon, Bandcamp, Discogs, Grooveshark, iTunes, LastFM, MySpace, Pandora, SoundCloud, The Hype Machine, Wikipedia, or YouTube by selecting some text and giving it a right-click. It's that easy.
OMusic, the Online-Music-Player.
It is a music player in status-bar. It provides firefox with ability to play online mp3 music(local file as well), to search and display the lyrics automatically, as well as to manage the music lists.