Sjaak built this blinky heart for his girlfriend this Valentines day. It is based on a MAX7219 and a PIC16f1823:
My girlfriend persuaded me to start this hobby side project and as a favor I made her this blinky heart. I don’t want to buy a standard trumpery from the shop, so I locked myself up into my mancave and started to solder and code as a monkey. I put a MAX7219 8×8 LED matrix, a PIC16f1823, a CR2032 coin cell with holder and a vibration switch together. Most of the stuff I had already lying around so I started immediately.
Somewhere on the web I found a small tutorial how to use the MAX7219 with the buspirate. That made it really simple for me to test the display for faults and get myself familiar with the command set.
Project info at SMDprutser blog.