PartyChat is a persistent chat room for GTalk. Basically what this means is that you can create a chatroom directly through the jabber client without having to mess with other things like web clients.
The bot itself does the entire conversation relay and if you exit from the client, you will still be joined to the last room when you relogin to your client unless you exit from the room itself (thus persistent). From what I can tell, it’s basically just a relay bot similar to an eggdrop for IRC or what not.
It is open sourced so if you think you can do better, definitely take a shot at it. All you have to do is add the bot to your Jabber Client and feed it some commands and away you go. Kind of like SmarterChild actually.