Grapevine's domain is one's own mouth, or the telephone. He's into gossip of all kinds and loves hearing the latest juiciest bits about what's going down, anywhere and everywhere. Lately he's branched out into the internet, message boards and blogs and anywhere one can spread information, especially if it's exaggerated or not entirely true. He also dabbles in the press, though not so much for the legitimate newspapers (other than the gossip columns). Mostly he's got his fingers into the tabloids.
Appearance: Grapevine takes on all kinds of guises and no one is quite sure which one really is him. Sometimes he appears as an old housewife, other times as a tall reporter with a notepad. You'll always find him with some kind of writing device, such as a clipboard or notebook and pen. Though lately he's taken to more modern devices, like laptops and cellphones.
Shamans: Shamans dedicated to Grapevine are very dedicated gossips, all of them. Tell them anything and you'll find the news spread around town faster than you can say 'Telephone'. None of them can keep a secret. In fact, they aren't allowed to if they want to remain a shaman of Grapevine's, cause he wants /all/ the latest gossip.
Summoning/Communing: The best way to get Grapevine's attention is to cast a circle and whisper 'Hey, have I got some gossip for you!'. Grapevine will usually come running.