I think the office is the only place I go "cute" halloween. Stick to happy pumpkins and smiling scarecrows and you'll be fine. Oh and let's not forget the dancing skeleton with the tophat!
I think almost anything bought at the big box stores (Target, Wal*Mart, K-Mart) would probably be appropriate for a work display, as long as it wasn't too gory. Leaning more toward a 'fall' display as most commerical places don't want to go too extreme. A couple of straw bales, some pumpkins, ghosts & corn stalks.