Other Web 2.0 Applications

I had a play with last.fm - http://www.last.fm/home - as a Web 2.0 tool. It won 1st place in the 'music' category of SEOmoz's Web 2.0 awards 2007 (a little old now, but I hoped it was still good).

Last.fm is a social networking music recommendation service. You create an account profile, enter some of your favourite music artists, and start playing some tunes through the last.fm player.
Last.fm can recommend other artists you may enjoy based on what you have listed, but the service really gets specific through use of 'The Scrobbler', last.fm's own music tracking tool. By downloading The Scrobbler, last.fm can then keep track of every song you play, how often you play it, how often you play similar artists, how similar your tastes are to your friends etc, and then recommend other music you may like based on the results. Use of the The Scrobbler makes last.fm's music recommendation service quite specialised to each profile, and bases it on 'hard evidence'.
You can also import your listening history to The Scrobbler's 'memory' using your iPod or PC media player.

The social networking part is that you can join discussions, comment on artist pages, and make 'friends' with others who are like-minded.

The biggest thing to like about this service is that hopefully you can uncover some awesome new music you didn't know you liked, based on what you've been listening to. It's fairly easy to use and download The Scrobbler. I'm still not clear about licensing for all the tunes you are able to play...perhaps worry about that later.
Overall it's a cool idea, and you probably end up with things closer to your personal tastes than if someone was to say "oh, you like this & I do too, so you should also like this because I do too".

But therein lies the other side of music discovery - you sort of lose the magic of stumbling onto something that someone suggests, or you randomly hear in the music store, or read about an artist that seems like they might be your cup of tea.
Also regarding how last.fm makes recommendations based on what you have already listened to - if my real music-listening life had followed that pattern, I'd have missed out on some good stuff. Just because I've been lost in a sea of alternative-rock/metal stuff for days, doesn't mean I can't appreciate some more ambient/synth-based/roots or whatever now and then.

I would recommend this to others, therefore, who have a love for specific genres, and want to know if there are any uncovered gems they don't know about (and keep your last.fm player to that genre).

How could I use this in my job - um...
I guess if there was a similar book-reading tool? Put in the books you love, and the service will make recommendations based on what you're read? Again, good if you're into a narrow literary field, maybe not so good if you're quite eclectic.