Skype has released a Beta version of the popular VOIP software for Windows Mobile 5.0 based Pocket PC and Smartphone devices.

New features and improvements include:

-Support for Windows Mobile smartphones - New
-Enhanced today/home screen: presence status, event notification (missed calls, new chat messages and voicemails)
Proxy support: Supports regular HTTP or HTTPS proxies, and authenticating HTTPS/SSL and SOCKS5 proxies - New
-Multi-person chat: Users can have multichat sessions using animated emoticons. When mobile users are offline, chat messages will automatically update the next time user logs in;
-Profile personalization: Users can take a picture with the camera on their mobile device and immediately update their profile.

Download from here