This excellent service is working again!
When you sign up, you will be assigned a phone number. Use that number when filling out freebie/contest forms. If/when someone calls and leaves a message, it will be sent to the email you specify as an audio file to listen to. Simply delete it or call the person back. Now your personal phone number is safe!
Want to test it out? Gimme a call and leave a message. It'll take you to my voicemail and you can leave a message if you want.
And speaking of being safe, you are using a different email address when filling out those freebie/contest forms, right? If not, you can always head over to Gmail and create a free account.