YouMail.com is a free service that allows mobile users, to create personalized voicemails for different people or groups like family, friends or business.

It has the following features:

• Voicemail online and by phone
• Different greetings for different callers
• Ditch unwanted callers
• Lots of popular cool greetings
• Voicemail sent to your e-mail
   

You can choose how to pick up your messages:

• Online voicemail. You can go right to the voicemail you care about. Point, click and play.
• Online voicemail simplifies your life - easily delete messages that don't matter.
• Save using the phone for when you're on the go or not near a computer.

I'm been using their service for several months now and I'm very happy with it (FYI. I don't work for youmail.com)