[KenWittlief]

the banner sensors are little yellow boxes with a red lens - they send out a pulsed infrared light, and look for it to be reflected back - usually the carpet will not reflect it, but the tape or white paint will

the little sensors FIRST gave us that are about a 1/4" square with three leads are infared recievers that are designed to pick up the beacon from the center of the field - there is a whole page of stuff on those on the innovationfirst.com website - under FIRST robotics / documents / beacon section

they are a little more complicated - you pretty much need to wire them to rc_dig_in_01 or 02 and use the interrupt flags to detect when they change state - also they need to be enclosed because they will pick up the IR signal from almost all directions the way they are.