Yep. Costs $2.99 at Tower.
http://www2.towerhobbies.com/cgi-bin...?&I=LXL468&P=7
Set the horn where you want it (holes lined up on the hinge line). Stick a "T" pin through any hole. Place the reenforcement pad where the pin comes out in the mating hole on the pad. Drill the other hole(s) out using the finger drill by drilling halfway through from each side. Remove the pin and drill the final hole. All done.
This little drill is handy for all kinds of small holes.
I've really come to like the control horns that use #6 or #8 bolts with one hole. Strong and simple.