http://www.youtube.com/watch?v=3D1V0yRJspOyA

I've made one of these with two 20-turn air coils (0.63mm enamelled
wire), 15mm diameter, transmitter centre-tapped. Standing current is
32mA @ 5V, rises as the receiver is loaded with white LEDs and a
PIC. Good place to start experimenting from
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.