I run triples on almost all of my bikes. I don't really need them in central IA but I like to find hills to ride in when possible. It also allows me to run a smaller freewheel or cassette in the rear than I would if simply running a double. I have one bike set up with a compact. I like it but 16 teeth is a big jump. I may switch that bike over to a shimano road triple.

Tripleizers are also available (and very useful) for old school cranks like campagnolo (144 bcd on the outer rings) and a stronglight 93 (which IMHO is a beautiful crank with a 122 bcd):

About Triplizers - Red Clover Components