I want to write a program under Win/Mac/*nix, that takes a phone number and dials it on my mobile through Bluetooth. I don't know much about BT. Is that possible? The mobile is mine and I WANT it to dial. How would I go about it?
You probably want to fetch your mobile phone manufacturer's AT command set manual. You then need to open a serial connection through Bluetooth (OS X: Connect with phone, /dev/tty.nameofyourphone should appear). You can talk with the phone as with a regular modem and send commands as specified in the documentation.