I'm deaf, so this application is very useful to me.
(For those curious, check out my FAQ at
Hearing Impairment FAQ by Mark D. Rejhon )
I have spare old BlackBerries without cellphone subscriptions that I'd like to impromptu-loan out to my friends when chatting in a bar, dinnertable, meetingroom, and other environment, especially in situations where I would otherwise be improvising communication method (because of it being too dark to lipread, too many people talking, etc.)
I'll do some research if BlueChat actually works. It appears to require OS 4.2 to work on a BlackBerry (because of Bluetooth in generic MIDP applications are not supported on OS 4.1 BlackBerry), which is unfortunate, and I only have one BlackBerry capable of running OS 4.2 (model 8700), which is a shame because I was hoping to utilize some old 7290's for this.