TalkerApp has a very interesting feature, users can create little javascript extensions that allow them to extend chat.
This would allow for stuff like extended oneboxing, syntax highlighting, sys tray notifications, keyboard shortcuts and so on.
As it stands users have already started extending chat with user scripts, the trouble though is that this is not that accessible as it requires a per machine, involved setup.
Could we build a simple extension mechanism where users can submit scripts to a central repo, and end-users select which scripts they want to run?