I work at a library cooperative, and we always celebrate birthdays each month, sometimes with pot-luck; other times we send out for chinese or mexican food.
Plus, we always seem to have something going on each month to celebrate some holiday... next up is Mardi Gras....
Unfortunately, we can't have a grill on our property (management co. rulz) so potlucks are normally stuff that is cooked at home and brought in to the office in crockpots - although last year we celebrated opening day of Baseball season with Ball Pak Franks cooked on a George Foreman grill.
I'm dancin', I'm dancin'!