In my N73 i have this prog called Mobiluck that looks for nearby bluetooth devices, when one is found, if it can receive calling cards, it will be listed, with it's type identified (mobile phone, smartphone, computer etc) and i can send it a msg as the name in a calling card (it's called "bluejacking"), the idea is the name of the calling card will the shown on the screen of the receiving party even before they accept receiving the calling card, thereby delivering the message. You can do it without any specific program, basicly jsut create a contact with the name field containing the msg and then send it via bluetooth to your target; but a bluejacking program like Mobiluck makes the task simpler as quicker, it already knows who is around before you try to send a msg (so you don't waste time looking for the target after you wrote the message), and it automates the creation of a calling card to send, it also centralize other things like sending fotos, it also sends msgs inside text files and a few other things. Oh, it also has the option of sounding an "alarm" when it detects a possible target.

And if you can think of other features to add, go ahead