Yamigo release 0.1 features:

• Implemented based on OMA Wireless Village specification release 1.1 read more here http://www.openmobilealliance.org/WirelessVillage/downloads.html
• Four-ways login sequence. Logout and disconnect.
• Clear text PWD authentication scheme. MD5 not fully compliant yet.
• Send and receive mobile to mobile messages
• New Message Delivery method "Push". Polling message every 90 secs.
• Session and transaction management
• Connectivity to external chat servers. Reverse proxy functionality for AOL, MSN and Yahoo. You need to provide login name and password for those external systems. Communication is supported both ways with these systems, yet no presence information is trasfered between them. Hmm, only Yahoo is tested OK so far.
• KeepAlive request for refreshing the session.
• Service and Capability negotiation
• Service provider information
• XML and WBXML supported
• CIR over UDP/IP limited functionality (is not working in practice due to operators NAT) Wait for IPv6 and 3G
• Supported bearer HTTP
• Limited search functionality. No paging support.
• Subscribe/Unsubcribe to presence information
• Presence update notifications
• Reliable messaging queue. Messages are kept in offline mode for one week.
• Only the Client - Server communication protocol  is implemented. There is no support yet for Server to server communication. Coming soon...
• For more information about the compliancy read here.

Registration via the domain pages. Account is activated immediately at no cost. Give it a try.