Boo!
It's that time of year, where kids dress up and beg for candy. I'm too old for that now (I get to buy my candy in the store), so now it's the time of year to make cool scary stuff. Make magazine has a fantastic Halloween Special Issue out, with instructions for all sorts of cool do-it-yourself projects. Everything from easy devil horns, to servo-controlled zombies. It's also available in book stores (with a different cover).
I also saw this neat trick online... making a magic mirror to hand out candy. Basically you frame a monitor attached to a Mac or PC running this voice activated program, that creates a floating ghoulish mask that matches your voice. There are other versions, but they're not free.