I know, you're probably too busy to watch Matt Cutts right know, so, here's the important part;
Q: Can you confirm Google uses Twitter and Facebook as a ranking signal
A:"Yeah, I can confirm it. We do use Twitter and Facebook links in rankings. But in addition, we are also trying to figure out a little about the reputation of the account and creator of the Twitter, Facebook account. "
Jumped to 18 from 35 for a 135k MS keyword.
Jumped to 11 from 32 for its domain name
Jumped to 3 from 6 on the fourth day of signaling
Jumped to 4 from 9 on the fourth day of signaling
Jumped to 8 from 15 on the 8. day of signaling.
Jumped to 5 out of nowhere on the 3. day of signaling.