Over at VoIPSpeak, there's an article describing how to set up Asterisk@Home, a distribution of the Asterisk open source PBX software for Linux, in a virtual machine on a Windows box. It uses the recently-released (and free) VMWare Player for virtualization.

Note that Asterisk@Home is actually a bit of a misnomer - it's more like "Asterisk-Plus" - a package of the Asterisk PBX with many of the more common and popular add-ons and enhancements packaged up. Installation is simplified and the heavy lifting is mostly done for you. Running in a no-cost VM environment, it's really easy to mess with and learn from. Set up a couple soft-phones and you'll be able to try it out all you like.

(via Digg)