I'm personally somewhat of a fan of Freenode (formally Open Projects Network), and it seems appopriate for SITO collaboration thingies, as per the charter:
freenode exists to provide an interactive environment for coordination and support of peer-directed projects, including those relating to free software and open source.
Generally one accesses it through irc.freenode.net.
![[nar SITOme]](/sue/imgs/sueid/suebar-nar-id.gif)