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.
First off, let's take a look at Social Butterfly. This one lets you chat with random users via Google Talk.
Next up, we have GroupBuyDaily. This one helps you find daily group buy deals in your city via a mapping interface.
If you're looking for answers, you might want to try out Askives, a social question and answer mashup.
APIs: Bing, True Knowledge, Yahoo BOSS. More at our Askives profile.
If you're a sports fan that likes pictures, Phanoto may be for you. It's an event-based photo sharing mashup based around sporting events.
For another way to discover new music, you might try biblify. It creates Spotify playlists based on the reviews of the newest albums.
Last but not least. Places from Facebook lets you check in at places, search places, and do other fun things using the geolocation aspects of Facebook.
Well, go on out and have some fun. I hope these can help you save time and have more fun using the social web.