I've been using Google+ Voice for years. The only requirement is that you have to have a Gmail account. And it's free. Makeup some bogus dontbotherme@gmail.com email, sign up for a free phone number and BOOM.

THAT'S the info you give out to people who are NOT family or friends.

I don't even use all of the features that it has like setting time restrictions on when you will and won't accept calls, etc.