I spent eight years on a project managed by an "accountant".  If offices were being shuffled and moved, every engineer, physicist, mathematician, and computer geek on the project came to work in jeans and shoved desks, chairs, PCs, and cable around.  We used to say, we're the world's most expensive moving company.  But to the "accountant", it was easier to steal our time away from the deliverables we were supposed to be working on, than to hire a couple of guys to come in and be done with it in a day.

One type I haven't seen discussed yet are what I call the "Furies", after the hateful pseudo-deities of Greek mythology who chase the hapless protagonist forever with scourges.  These customers are not smart, and they are definitely not your friends.  Nothing you do for them is ever fast enough, or good enough.  Their conception of what you do is "point and click".  Since it's fast whenever they point and click to a mature application, it should only require that you point and click an entire database into existence, complete with everything they haven't thought of yet.  Some of us techie types are neurotic, in that we might tend to think if we don't understand a technology, it might be that it's over our heads.  The "Fury" doesn't have that problem.  A true "Fury" will assume that if she doesn't understand a technology, it is therefore simple.  And a "Fury" would rather be tied to fiery log and force-fed her own spleen than think through a list of requirements, put them on paper, and sign them.  That would just get in the way of months of recriminations, during which time you'll hear the following phrase many times:  "We changed that requirement -- I'm sure I sent you an email."