1. Freeze the sweets. Chocolate freezes very well, and you'll have several months' worth of desserts for your brown bag lunches stashed. Put hard candies or sweets like Skittles, Starburst and Nerds into tightly sealed bags; they should stay fresh for quite a while.
2. Bake with it. Chopped or crushed, a chocolate- or peanut-based candy can do lovely things for cookie, brownie or cake batter. Use Skittles et al. to decorate cakes or cupcakes.
3. Ice cream enhancement. The same crushed/chopped candy makes a tasty topping on frozen yogurt or ice cream. Or whirl those ingredients in the blender with a small splash of milk for a home version of the McFlurry. Even the cheapest store-brand vanilla ice cream or fro-yo will taste good with those sweet add-ins.
4. Doctor your drinks. Drop a mini chocolate bar into your coffee or a peppermint patty into your cocoa.
5. DIY Advent calendar. Fill a refillable Advent Calendar with leftover Halloween candy in each of the cubbyholes. Betcha the kids won't seem to notice the candy's provenance.
6. Weird science. Microwave a Peeps candy to explain the action of gas molecules. Create a "Mentos geyser." Check "10 scientific uses for leftover Halloween candy" on the Science 2.0 blog for other fun experiments. Teachers: I bet a lot of parents would be happy to donate candy to the classroom.
7. Take it to work. Leaving candy by the office coffee pot is a time-honored tradition. Alternate idea: If your workplace has a candy dish at the front desk, seal your surplus in a plastic bag and give it to the receptionist.
8. Take it to the fire station. Firefighters need fast energy, right? But seriously: Call and ask if they could use it, then let your kids do the giving. Fire trucks are just exciting. (And if you're single, this might be a chance to strike up a conversation.)
9. Take it to the food bank. If someone can't afford groceries, he sure can't afford a piece of candy -- and a little treat can make a big difference when money is tight. And speaking of making a difference...
10. Sell it to your dentist. A program called the Halloween Candy Buy Back encourages dentists to buy sweets from kids; the goodies are then shipped to deployed soldiers. Some dentists pay cash (usually $1 to $2 a pound), and some give small gifts. The website has a search tool to let you find a participating dentist near you.