Here's a video of it in action:
Open Heart kit or make your own
LilyPad AAA power board
scraps of fabric
safety pin or pinback
USB cable regular to mini
hot glue gun
Step 1: Assemble the Open Heart
Step 2: Assemble the heart/lilypad sandwich
Step 3: Sew the sandwich
Sew those same pins together, hiding the knots between the two fabric layers so they don't flop around and short out your board.
Step 4: Adding power
I used two more pieces of stranded wire to make the dangly connections between the battery board and the main board. I had to bridge the + on the battery board over to one of the unused pins on the opposite end of the battery holder to keep the dangly wire supports symmetrical. I used conductive thread for this; you can see it on the back of the battery board.