All BlinkM-family devices can have their firmware updated. This makes them great for tiny development boards for ATtiny processors. ReflashBlinkM is an application that makes it easy to put back the original firmware or update a BlinkM to the latest firmware. Previously you needed an AVR ISP programmer like the AVRISPmkII or the USBtinyISP. Thanks to the ArduinoISP sketch that ships with Arduino, if you have already have an Arduino, you can easily reflash your BlinkM with new firmware.
The ReflashBlinkM application is a tool for Mac OS X and Windows that uses ArduinoISP to help you reflash BlinkMs to their default firmware.
This is what it looks like:
Here's one way of hooking up a BlinkM to an ArduinoISP:
And here's a video of a BlinkM MinM being reflashed: http://www.youtube.com/watch?v=PMBtjAPBdwI