You're at a restaurant and you hear a dope jam on the speakers. The hugely (and rightly) popular Shazam iPhone app lets you "share" the item and take a photo, but it needs more integration with the wider Internet.
Shazam as a web service with an API (all it does is store name of the song tied to the location). Then through machine tags you can tie in Flickr photos/sets, list them as listened-to on Last.fm,
AudioBoo lets you do this without the song recognition part:
you can post images, location, tags to a 'boo'.
would rather have it separated out amongst web services, giving you some of the functionality all of the time.
James Darling got this working, though it involves packet sniffing, not exactly an accessible technique to submit information to Last.fm. http://skillsmatter.com/podcast/ruby-on-rails/packet-sniffing
Similar (original? complementary?) idea: http://www.darrenbarefoot.com/archives/2008/03/songlines-or-tracking-musics-movement.html
Shazam + Twitter + individually-geotagged tweets?