Extension.fm, a Chrome browser extension we first wrote about in February, has launched to the public and announced that it's received funding from a group of high-profile investors, including Spark Capital, Betaworks, Founder Collective (Caterina Fake, Chris Dixon and others) and Dave Morgan (founder of Tacoda and Real Media).

Extension sits in your browser and automatically grabs the links to any music files you see around the web, rendering them easy to play later through a special interface. Based in New York, the company is lead by Dan Kantor, the creator of AOL-acquired Streampad and the feature in Yahoo's Delicious that renders links to MP3 files playable.

With that kind of background and backing, it's hard to imagine there's not a whole lot more in the company's plans than a Chrome extension. That said, the Chrome extension is very impressive and Chrome is the best browser on the desktop.

Extension is most appropriately described as a music discovery service. It's not for listening to bands you already know and love - once you get access to Spotify, there's no other game in town for that, except perhaps Mog. But if you're a person who likes to peruse blog posts and other pages where new music is linked to, the Extension makes listening to those songs systematic and very enjoyable. It lets you capture and listen later to all the new music you stumble on while zipping around the web. Separating media from its initial place of discovery, temporal displacement for more conscious media consumption, is probably something that video files could benefit from as well. Time will tell if Extension gets into that business.

With the investment, Spark Capital's Bijan Sabet will join the Extension Entertainment Board of Directors. Sabet lead Spark's previous investments in Twitter, Tumblr, Boxee and more. He wrote about the investment on his popular blog today.