I've been partial to Heinlein's idea of the "general specialist" lately:

"Computermen sent up to install Mike were on short-term bonus contracts— get job done fast before irreversible physiologlcal change marooned them four hundred thousand kilometers from home. But despite two training tours I was not gung-ho computerman; higher maths are beyond me. Not really electronics engineer, nor physicist. May not have been best micromachinist in Luna and certainly wasn’t cybernetics psychologist. But I knew more about all these than a specialist knows—I’m general specialist. Could relieve a cook and keep orders coming or field-repair your suit and get you back to airlock still breathing."

from The Moon is a Harsh Mistress