After watching Wayne find two interesting tracks in a row by putting out tentative feelers on Twitter, I think I might be sold. Facebook updates are all good and fine, but those hashtags and @-prefixes seem designed precisely to help you find information in interesting and directed ways.
Of course, publicising your tweets on your blog probably helps too. Here's my first query:
!Un Saludo! Mexican Soundsystem Cumbia in LA
2 weeks ago