Please add the BlackBerry phone browser to the list of mobile browsers detected by chat.SE and redirected to the mobile site.
The BB OS5+ browsers are webkit-based and actually work pretty well with even the full chat app. The main problem is that the screen is too narrow for the chat layout:
Even if the browser is unsupported, it would probably benefit those (few?) users of chat.
Various BlackBerry User-Agent strings mention BlackBerry and Webkit.