I’ve actually been using these two services for a while now.
http://www.privatephone.com is a service that gives you a free personal voicemail box. This way, you can give out your Privatephone number anywhere that you’re not comfortable with giving away your real phone number.
http://www.grandcentral.com is kind of different. You get a number and it will forward to whatever other phone numbers you want it to go to. And you can set times for when it’ll call what number. You also get a voicemail box with this too.
Pretty neat services. I use them both. My GrandCentral number actually forwards to my Privatephone number. Hehe. That way, people really won’t get my real number at all.