bluetooth project

Hi guys, I really need help on a project i want to work on.
i have in mind a bluetooth message box. this would dispatch messages to discoverable devices within range, much like a bulletin box, notice board whatever. the target device are actually phones. could any one help me with what the circuit diagram would look like. or even a block diagram. components involved. is it that cost intensive? i really need help and would appreciate it thanks a lot.

how big?
what is the price range?

The easies way is to use some PC with windoze or linux with BT. You can for example use PC Engines alix3d3 product file with BT dongle. Write your software in your favourite language for your favourite operating system.

Doing this any other way will be big hassle, very complex and much more expensive.