M.O.
There are two such devices I've ever seen - the one you are probably referring to is a sort of leather "cage" that can be installed on the pedal to hold the toe part of the shoe onto the bike. This way he can wear any shoes he wants to, just by sliding them into the straps/clips.
I think this may show pictures of what you are referring to: http://www.google.com/products?q=bike+toe+clip&oe=utf...
I just searched bike toe clips. If I were you, I'd go to any bike shop and ask for what you're looking for, at least the first time so they can give you some advice.
The other style I've seen are for the more "professional" bike riders. They are actually pedals and shoes that clip together - the rider snaps the shoes onto the pedals so that their feet don't come off and they can really pull up and down and use their strength for long rides.
I hope this helps!
Sara