Quizzes often work well (adapt questions to suit audience). We've done the "baby-photo" in offices where I've worked and that's always been successful, too.
Another idea (similar) is to cut ads out of magazines but removing the brand name or product, and people have to guess which product it is. (With a lot of ads it isn't always as easy as it sounds.)
Another old favourite is to pin the name of a famous person (living or dead) on people's backs as they enter, then they have to ask others about their identity; but the respondents are only allowed to answer YES or NO. You have to deduce who "you" are. Usually no prizes, but great fun. (This probably comes under "kids party games"). Actually I think all this sort of thing tends to go down quite well, but you know your audience, and the most important thing is that no-one feels left out.
Hope it all goes well.
P.S. Can I come?