Also, if you have another jabber client like Trillian or Exodus laying around, you can connect to the server 'talk.google.com' on the normal jabber port and use it that way, which offers a more powerful interface to Google Talk.
Also, as you can see there is message continuation, which means if you type twice in a row it all goes into the same message. (Sort of annoying)
In the end, all this is is some guy setting up a jabber server on his box and moving the gmail accounts database onto it.