Orb Networks recently came out with a voice mail service that sits on top of Skype. As you well know, I'm a huge proponent of the Skype service and use it quite a bit (to the point where my next set of business cards Will include my skype id). The problem with the voice mail provided by Skype is that it's an additional cost. V4S (voice mail-for-skype) is a free service...with a catch.
The catch is that in order for you to actually receive the voice mails (in your email box or other streaming device), you must have an XP machine "always logged into Skype". I currently use a Mac 90% of the time, and do have an Windows machine primarily used for running reporting software, but I don't plan on having the machine logged in permanently to Skype.
I don't think this is going to scratch the voice mail revenues from Skype (although I don't know of anyone that uses that feature) because of this limitation.