I have tested many VOIP solution in my tenure as a technical operator, but few have rivaled the latest offering by Google, and none can match the price.
I am talking about Google Voice which can be found at www.google.com/voice this is a service that is great for consumer as well as commercial applications. If you are a small business and looking for a very cheap voice mail solution that can follow you anywhere Google Voice is the ticket.
I was a beta tester for the service and now have several numbers for my SMB web sites. Having a real number that customers can call you for your web products is a real deal closer. I have seen my close ratio increase by 20% by just adding a phone number.
Best thing is if you are busy it transcribes the voicemail and sends you an SMS message on your smart phone, and did i mention it was free.
All in all this is one great service and i highly recommend using it for your SMB or web site contacts.
Have a great week!