Since there was no Google Visual Voicemail application available, XDA developer Sl4sher decided to make one himself, because he found it to be a pretty good way to handle and manage voicemails.
The new application uses a Sense SDK to get a nice looking interface, and offers the ability to show a list of all voice mails, mark as read, delete, and more. Nearly every (decent) device is supported, as long as you have .Net Compact Framework 3.5 installed. It is confirmed to be working on the Touch Pro2, Treo Pro, HD2, and more. However there might be some bugs.
Originally posted by Sl4sher
Google visual voicemail is a semi-offline client for Google voice. You can view and play your voice messages as well as mark them read/unread and delete them.
When updating, message text is downloaded to a local cache that can be viewed at any time. Audio is downloaded the first time you click play and is stored for future use.
You can find the download, installation instructions and known issues in the application thread.
There you can also post feedback and discuss the application.