[Video Link] Burner is an iPhone application that lets you generate temporary phone numbers. This would come in handy, for example, if you are selling something on Craigslist, and you don't want to give out your permanent telephone number. The app costs $1.99, which gives you a "burner" number that's valid for 7 days, 20 talk minutes, or 60 texts, whichever comes first. You can buy additional credits in the app.
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects