If you are looking for sound samples on the web and want to add them programmatically to your apps, the Freesound API may be just what you need. Freesound is a collaborative database of Creative Commons Licensed sounds. Users can join Freesound and upload their sound files and share it with others. Recently it also announced that it has crossed 100,000 songs in its database.
There have been a lot of new socially based mashups showing up recently. In fact, we recently topped 700 social mashups. While many of these use the Facebook API or Twitter API, there are many more social APIs. The mashups below run the gamut, though, yes, also include Facebook.