daedene - it is surprisingly hard to get people to gather to learn as opposed to just taste. So one option is to learn all you can from those events where people are just gathering to enjoy wine and company.
But you can still make that kind of interesting. I'm assuming you have access to a lot of CA wine, so what if you gathered up some Merlot from Oakville, Rutherford, and say, Alexander Valley. Get like 2 or 3 of each, all from the same vintage and see if you can detect any similarities or differences between them that might be attributed to the different regions. You can do that with wines from anywhere in the world actually.
Or find some wines made by the same wine maker in different places and see if you can identify his or her hand. If you pick someone like Phillipe Cambie, who seems to make hundreds of wines in the south of France, you can do it inexpensively.
You'd have to do a little research online to find out what comes from where, but that's a learning experience too, and you can order online if the stuff isn't available locally.