Actually, I've been very guilty of this... I solved it by quitting my job!
I was working for a government contractor in transportation (trucks, buses etc). We had numerous contracts and I worked on all of them plus did all the training and assisted in the bid process. I was getting worked to death. I traveled four weeks per month (do the math...) for five straight months plus work on the weekends. I was sick, frustrated and exhausted. With the economy as it is, I was definately not going to take a "leave" of any sort without something else lined up.
I asked to have two weeks per month at home (working) and two weeks out. I was denied.
So I took my little skill set and went somewhere else where I am treated like a human being and not a bottomless resource.
angela