CFL bulb: Wear shiny white body suit and electrify hair in some way (Bride of Frank wig?). Build CFL filament around yourself, using white foam tubes, stuffed white fabric/socks, or white balloons.
Glacier in 2050: Carry glass of water.
Prius owner: Dress in clean, tasteful clothing and walk around with contented air, holding Prius key casually at chin level (pain small matchbox black and write "Prius" in shiny letters or, if you have actual Prius, write "Prius" on key). Stuff pockets with with overflowing money saved on gas. Click here for Fisk's full list.
Grist isn't the only one telling readers how to make their Halloween more green. About.com also has a list of Green Halloween Tips that includes the following: 1) Trick or Treat with Reusable Bags; 2) Make Do-It-Yourself Costumes; 3) Give Eco-Friendly Treats; 4) Walk Instead of Driving; 5) Make Your Halloween Party Eco-Friendly; 6) Reuse and Recycle; 7) Keep Halloween Clean; 8) Keep it Going. Click here for About.com's full list.
Green Halloween also has a whole website dedicated to offering fun, healthy, affordable and easy costume ideas that benefit both kids and the planet.
Good luck on the costume search and party preparation. We look forward to seeing your green ideas out there on the 31st!