I found Grandaddy by using Amazon’s collaborative filtering technology – when I bought a Flaming Lips album on the advice of a friend, the Amazon filter said “folks who bought ‘Yoshimi…’ also bought…” I bit, and am glad I did. Now, take this idea to search, at least in a way. Thanks to Scoble for this gem: MusicPlasma. More proof of what can be done on top of a search platform. This takes a Grokker-like interface to show how your musical tastes relate. Type in one band you love and it will show you others you’d like. You can drill down in sort of a Venn diagram-driven search – say “Radiohead” then “The Shins”. As far as I can tell, this is built on the Amazon API (perhaps someone more astute than I can figure this out?). This is why, as I will say again, Yahoo and Google should really rev up their API programs.