I'm inordinately proud to show you my first switchcraft project I did tonight: a wristband with a couple of LEDs sewn onto it.
Using the lilypad e-sewing kit, it was easy to throw this together. Probably the hardest part is threading the thick 4-ply conductive thread onto a needle. Otherwise, it's just hand sewing the positive and negative paths of the circuit onto the fabric and making sure they don't cross or the whole thing will short circuit.
The two LEDs are powered by a 3 volt battery held in a case on the reverse side. I could have easily put in a switch, which will be my next project.