Oh man, that sounds like fun. I have a bunch of friends that go every year, invite me every year and something inevitably comes up…..every time.

At any rate, three wineries on MY must see list (if I ever get there)….

Siverado – One of my favorite wines.
http://www.silveradovineyards.com/index.html
Lamborn – the best damn zin made, bar none. Great folks, one of the best wine makers in the business (Heidi Barrett).
http://www.lamborn.com/cs/lamborn/view/docs/9
Mondovi – take their wine tasting class.