Along with iChat, Yahoo! Messenger is the only instant messenger out there (at least well known) with video chat support (supports iSight). Although audio is currently unsupported (promised for the final release) and frame rate is a bit jerky, this is a nice attempt. Most importantly, this version of Messenger looks much nicer than Windows counterpart and behaves like a good Mac software would. There are some feature disparity against the Windows version, but this is a good way to amend with Mac community.