Uncylopedia, the self-proclaimed encyclopedia "full of misinformation and utter lies", has a hillarious article about Geologists. I especially like the "Geologist-Engineer Controversy" which, having worked with both geologists and engineers extensively, is a pretty accurate portrayal of their respective approaches.
Geology, being an art as much as a science, has always baffled and worried engineers, hence the engineers' defensive weapons of pocket protectors, slide rules, black socks, and eventually computers.
A related joke:
A geologist and engineer walk into a job interview. They are each asked a simple math question : 'What is 2 times 2?'. The engineer replies, 'It's 4.00000'. The geologist replies, 'Ah.. it's about 4'