We drop into a number of private house parties of about 20 every New Year's, but none with sit-down dinners that close to midnight, if I understand you correctly. Rather, they have extensive buffets, and people are eating all night as they come and go, which itself is entertaining. And of course an open bar, self-serve or with a bartender (though watch the drinking; in some jurisdictions the host can be partially liable for the consequences of drunk driving afterwards).
This year one gay couple we know will be celebrating their official married status at midnight, January 1st, so that will be an important focus of our evening. Other things we do is have a pianist, as many in our social circle are in gay choruses and love to sing. Indeed, we did just that this past Sunday, at a private holiday dinner party for about 16 of us. Lovely lounge-type music during our cocktails, and a few guys drifted over to the grand to sing a lyric or two. No one danced, but that's another possibility, either indoors or outside on a patio, if your LA weather permits.
Another thing you can do with a smaller group is provide party hats, noisemakers and other favors. At a party last year our hosts had novelty eyeglasses that read "2009" with the double zeros where your eyes were. Won't work with 2010, but I'm sure there'll be something else this year.
Some cable or satellite TV channels will have live coverage & replays of New Year's celebrations in major cities, as midnight advances around the globe, and I've seen hosts have that showing in the background. On the West Coast you can have Times Square at 9 PM, and other US cities at 10 & 11.
Other than that, all our friends entertain themselves with conversation, and would find structured activities a distraction, if not an actual annoyance. So have good music in the background, live or recorded, hors d'oeuvres and drinks, and you should be OK.