Can you help me plan this event?

Every couple months, my department holds a social event. Everyone is invited to gather over beer, wine, and some kind of food. Next month is my lab’s turn to host, and I’d really like to come up with some kind of theme, if possible!

The obvious theme for us Southern Californians (Mexican) has been done multiple times, so I’d like to come up with something new.

Also, we have a very limited budget ($150 for alcohol and $500 overall), so if you have any brilliant cost-saving measures, I’d love to hear them.