Brett Oliver shared one of his Master Clock projects on the Adafruit Forums, featuring an Adafruit Bluefruit EZ-Link unit:

I have used a Bluefruit EZ-Link – Bluetooth Serial Link in my latest Master Clock. The clock is wall mounted away from my PC so I have used the Bluefruit EZ-Link to program and read the clock remotely with my PC. I can also read the clock with my Android mobile phone.

Read the complete documentation of the build back at his site.

Featured Adafruit Product!

Bluefruit EZ-Link – Bluetooth Serial Link & Arduino Programmer: We are excited to add another product to our growing Adafruit Bluefruit line, this time it’s the Bluefruit EZ-Link: the best Bluetooth Serial Link device ever made. Like you, we have purchased all sorts of Bluetooth serial link modules, with high expectations – we just wanted something that worked! But nothing ever did exactly what we wanted: there was always some configuration modes to wade through, and using one of those other modules to reprogram an Arduino is impossible. (read more)