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:
Shazam + Twitter + individually-geotagged tweets?