half-op can be really usefull in large channels but often serves no purpose on smaller ones. the big advantage of such a level is that it doesn't grant too much rights, while still being able to keep a channel nice and clean. this way you can have a few operators who can really control the channel, and a bunch of half-ops who don't have to do any more then kick troublemakers.
I myself never use them since I don't frequent channels large enough to need this.
we (a group of people I'm with) do use it as another channel rank to let new people know who has which rank inside this group.
most networks I'm on do not support half-op though and I can't be really bothered with it either :-P but it sure has it's uses.
