Our vendor suggested to make a tile that shows how many calls hit a Call Routing announcement which transfers to voice mail... but a) that didn't work correctly and b) wouldn't really tell you about messages left anyway.

We use the e-mail gateway to collect voice mail messages outside of the PBX so we have a rough idea how many and how large and of course I can see each mailbox stats through DB Programming but would be nice to throw some stats up on a monitor somehow.