I celebrated Halloween by working late. Exciting, I know. However, here are a couple of good links for Halloween-related fun:
Finger cookies - These seem to be popping up everywhere, and I even got to eat some this year. Now I have a recipe! (via Jill)
A scary Halloween costume - I agree completely with Orac.
Halloween movie clips about science - from PZ Myers; the last two are particularly good (if not terribly Halloween related).