I can't tell you how many times I've asked questions around here and other forums and never got the answer, then one day...well...I just found it! I have to share for everyone!
I needed to get a voicemail off of my SPRINT account. As you know, there is no way to forward a voicemail from SPRINT to any other carrier or an email address. There are times when a person really does need such a service. Sometimes you only need it once and don't want to have to pay for a monthly service for such a situation...especially when they make you input a credit card number up front!
Finally, here is your answer:
https://host1.gotvoice.com/signup/signup.php
Enjoy!