I have just signed up to be the Friday poster for this fine comm. I bring you a word I just learned today (via gutta_honey) as my first contribution:
Gossip hound: a person who seeks out gossip and then uses it for his/her own advantage.
From the Urban Dictionary (2006):
Someone who gossips incessantly. Usually a person with no life of their own, who enjoys wreaking social havoc amongst others. So completely untrustworthy, they cannot be trusted with even the most trivial of information. Often observed carrying a cell phone, and can text message at warp speed. Most often observed in females, but may include gay men.
"My girlfriend got overly drunk at the party, and fell down the stairs. Thanks to a gossip hound, by the next afternoon, everybody in school knew about it."