I’m planning a Fourth of July party, to be held in my house. The guests don’t all know each other yet, and some of them have very different interests. So far, the guest list consists of:
[ul]
[li]Roomate/best friend and her boyfriend[/li][li]Boyfriend and some friends of his[/li][li]Assorted sorority sisters[/li][li]Friends I’ve acquired in math/physics classes[/li][/ul]
We’re having a barbecue on our deck. It requires a drive to get to the nearest pool, so I doubt people will be doing that. Some of us drink alcohol and some of us don’t. Everyone’s between 20 and 22, a little heavy on the girls. The group should be large enough that it can break up into small groups of people who know each other.
What kind of activities can I plan that will be fun for everyone? Anyone know of any cool party games, themes, or ideas of what I can do after I feed all these people, to keep them from being bored? 
Thanks! 
Do you have a yard for volley ball?
For food, brats and burgers are good.
My favorite party game is The Hat Game. It’s a fun one for people who may not know each other well. Have every person write down the names of 3 famous people or characters and put them into hat. Divide the group into two teams.
Round 1:
One person from Team One picks a name out of the hat. They describe the person without using their actual name, while other teammates guess. (E.g., the Incredible Hulk: “He’s a big, green superhero.”) Team One has 60 seconds to guess as many names as possible. After 60 seconds, Team Two has a turn. This goes on until all the names have been guessed. When their turn is up, a new person from Team One has 60 seconds to describe the names in the hat. At the end of the round, put all the names back in the hat.
Round 2:
Same story, except that thsi time each team can only use 2 words to describe the person. (Incredible Hulk: “Big. Green.”) At the end of the round, the names go back in the hat.
Round 3:
Again, same as the other rounds, except that instead of words, this round uses charades. (Person acts like the Incredible Hulk.)
I’ve never had a bad time with this game, and drinkers and non-drinkers alike can get into it.
Sit two people, back to back, on the floor or ground. Then have them stand up, without using their arms or hands. They have to rely on each other to be able to do it. Once they’re up, have them sit again and add a third person and repeat. Add a fourth and repeat. Keep adding people until it’s not possible to stand. I’ve never tried this after drinking but it could only make things more interesting.
Another game is to gather everyone in a circle and join hands with each other, without looking. The idea is to get everyone untangled without breaking the chain.
friedo, I said they were from math and physics classes! You don’t play naked Twister with those kind of people! 
Kalhoun, we don’t have enough backyard to do anything more than lie on a towel, but thank you very much for the suggestion.
burundi and Jeff Olsen, thanks for your great suggestions!
Keep them coming, all! I’ve got a lot of people to entertain and few ideas.
Ooh! Ooh! Can I come? I’m mostly harmless.
We’ve had a great time recently playing Spoons. You’d need a table (or two) for this, but if you have the room, it can be a real riot. In case you’re not familiar with it, you lay out spoons in the middle of the table, one less than the number of players. Then you deal four cards all around. The remainder of the deck stays next to the dealer, who draws one card at a time and passes one on. The object is to get four of a kind. And you don’t wait to take turns. You just pass the cards on as fast as you can pick them up and check to see if you need to keep them. You can only have four cards in your hand at any one time, but you may keep any card that comes your way, provided you discard (pass) another one. The first person to get four of a kind picks up a spoon and then everybody else can grab one if they can get one. Sometimes the one who doesn’t get a spoon is out, but we usually spell out SPOONS with each losing time meaning one letter. First one to reach the full word is out.
You don’t really have to know anybody else at the table to play, and it gets everybody laughing and at ease.
Make sure your porch is structurally sound. This probably sounds crazy, but I knew of a party where the porch collapsed and people got hurt.
Now, back to the party …
Kegger!!! Good stuff like Heineken or Newcastle Brown.