At the risk of sounding like a complete tool, the best way to describe Twones, which launched Thursday, is "FriendFeed for music." The Amsterdam-based start-up aggregates a variety of social and not-so-social music services--currently a total of 28, including Imeem, iLike, Blip.fm, iTunes, Grooveshark, and Last.fm (owned by CBS Interactive, which publishes CNET News)--through a Firefox browser plugin.
Once you've set up your account, Twones (which I'm guessing is pronounced "tunes," rather than rhymes with "phones") will compile your playlists and listening history but will also, much like iLike, provide artist information, upcoming concert dates, and photos and videos sourced from Flickr and YouTube. You can also bookmark favorite songs and find out what your friends are listening to.
Twones doesn't actually host licensed music and the company doesn't seem to want to, which is good to hear: streaming music start-ups are, plagued by both legal issues and difficulty making money.
The moneymaking prospects for Twones, which has already taken investment dollars from the Holland arm of concert and promotion giant Live Nation, aren't yet clear. The company will serve ads, but hopes to also make money by offering premium accounts down the line for users as well as business accounts for artists and marketers who want more detailed information about who's listening to their music and who could be untapped marketing targets (among other things). But these are all obviously dependent on an active user base, and relying on an installed browser plugin may deter some users--especially since it's currently Firefox-only.
Twones is in private beta but we have 500 invites available for CNET readers. Use the promo code CNET09 when you register.