Simple VoiceBox is a service that provides a free voicemail box. You can use it as an announce-only message, or allow incoming messages. When I signed up through the company's web site, I was assigned a phone number in Iowa, which worked immediately. Unfortunately, the phone number isn't unique to you: your callers will need to enter an access code to reach your voicemail box. Simple Voicebox suggests using the service to record a message about your products or services, then giving that number to prospective clients. I don't know about that — the access code thing makes it seem less-than-professional to me — but it's a good way to score a free voicemail account.