Disposable phone numbers

I've used services such as Mailinator in the past to get a temporary, disposable e-mail address when I didn't want to give out my actual e-mail address. But what about when you don't want to give out your phone nubmer? Well, Craigsnumber is a service that will give you a phone nubmer that automatically forwards to your real phone number and expires after either one hour, day or week (your choice).

Why use a service such as this. One suggestion is when you're trying to sell or give away something on Craig's List and you don't want people calling you after the item is long gone. This is probably something I'll be doing in the next two months in preparation for my move to NE, so I'm thinking I'll give it a try. I'll report the results when I have them.