That's a classic. I've got to do that one next year.
I'm doing the Turkey Day Ride from the California Pedaler in Danville. It's a 30 mile ride but I'm starting from Garry's place in Dublin so it'll be a 48 mile day for me.
There's also the Los Gatos Thanksgiving Day ride (MTB) but I'm not sure it's meant to work up an appetite.
http://forums.mtbr.com/showthread.php?t=565576