If someone asks what time is it – you simply take out your Altoids binary clock and tell the time with no emotions. Seriously if this scenario seems attractive then this project is right for you. Linux-dude from instructables made one. Its actually Arduino based so he had to make custom shield for LEDs, buttons and buzzer.
He used different color LEDs for minutes and hours. Also he popped couple buttons that are used to set time and alarm. As you guessed alarm is sounded with buzzer. There is a lack of information about power supply. But since it is meant to be portable clock must be battery powered weather directly to 5V/3.3V or like 9V cell through voltage regulator.