Because I'm in the wine industry, I have been fortunate to meet and become friends with a number of people that are also very interested in learning about wine. This has lead to some really fun nights. I am part of a certain group that likes to get together once a month, and blind-tastes wine. What is blind tasting? It is simply tasting wine that you don't know what it is, and trying to, out of your own past experiences, ascertain what the wine is. Some people get all geeked out over single-blind versus double-blind. Single blind is where you know the varietal (say cabernet), but don't know anything else about the wine. Double-blind is where you don't know anything about it. The group that I'm in does both.
Here's how we do it-
we pick a night (usually a weekend, so people can sleep in the next day if they over-indulge), and a place. The host picks the theme. This last weekend, it was to bring any white you wanted, and a bottle of something cabernet-based. We then show up with the bottles covered with either foil or newspaper, and start pouring. The goal is to guess the varietal, country of origin, and vintage of each wine. It really is amazing how much stuff you taste in a wine when you are really paying attention. The whole thing is all in good fun. What I like about this group is that people bring cool, interesting things, and don't necessarily try to "one up" each other by bringing the biggest, baddest, most expensive wines. Don't get me wrong, cool stuff is definitely poured- we had 1975 and 1982 Bordeaux, Pride, Caymus, a wine from Lebanon, White Burgundy, White Hermitage, and all kinds of other amazing wines. I even tried to sneak a two-buck-chuck in there, to see what happened. Needless to say, it didn't win the "wine of the night" prize. However, the group didn't get mad- they laughed at it.
So, if you want a really simple, inexpensive party idea, give this a shot. It's a lot of fun, and you really do learn a lot about what you like and don't like regarding wine.