With addition of embedded XCAP server (xcap_server module), Kamailio 3.1.0 simplifies dramatically the deployments of SIP SIMPLE presence services.
A complete tutorial about how to configure Kamailio with embedded XCAP server and using it with SIP Communicator softphone was published at:
There are just few days left until the full release of v3.1.0. Stay tuned, it brings many new features!