You can get an auto expiring phone number for free at Craigsnumber.com Why would you want an auto expiring phone number? Well, the intention of the website, as you can gather from the name, is for people to use it when they post an ad on Craigslist. The poster can protect their identity and be easy to contact. The poster can chose to have the number expire in one hour, one day, or one week. It's a pretty good idea and I am going to start using the service.
What I thought was interesting about it was the "want a number your area code?" feature. You tell the website what city you are in and then it gives you a phone number with that area code. What I'm wondering is if this can be used to call long distance for free. If grandma lives in Jersey and you are in Cali could you sign up for a Jersey number for her to call you on as a local call? It's an interesting idea that I am going to have to try. (And yes I know 90% of us have cell phones, but it's still an interesting idea). If anyone tries it please post the results. Thanks!
***Update - I actually tried to do this today, and as of now the website only has local numbers for San Francisco, Washington DC, and Dallas. So I guess if you live there or know someone who does you're golden!