Trina's idea for crafts activities sounds great (I might take that into consideration for DS next birthday) - You could do a whole range of different things; making masks, hats etc. and it keeps them busy
Also, how about some of these games? Most of them are traditional English games but you probably have the same in the States under a different name.
"Chocolate hunt". Basically hide some chocolates around the house and the kids take turns trying to find them. Of course, if they find them, they can eat them
.
"Chinese Whispers" (can be loads of fun
) once you get the kids motivated. The kids sit around in a circle and one kid thinks of a phrase or sentence, like, for instance "Spiderman is cool". he then whispers it into the ear of the kid sitting next to him. That kid, then whispers it into the ear of the kid sitting next to him/her and it goes around the entire circle until it ends up back to the kid who started the phrase and he then shouts out the phrase he hears. The sentence ends up changing by the time it gets to the last kid with some quite funny results.
"Apple bobbing". Fill a bucket with water and put 4 or 5 apples in it. Each kid takes turns (with his/her hands behind back - no cheating) to grab an apple with their teeth!
"Pass the parcel." You wrap up a present (something that is good for girls and boys if it is a mixed party) with as many layers of wrapping paper and newspaper as you can. Kids sit down in a circle and you start the music (someone is in control of turning on and off the music). The kid who is holding the present when the music stops unwraps one layer of the paper. This continues and the kid who unwraps the last layer gets the present.
You could also do some sports like acitivities if you have a good sized garden. Egg and spoon race, three legged race, sack race, simple running races.
Hope this is of some help and that the party goes well. Good luck!