I'm with wsieber on this. Intellect is having the faculty to understand; intelligence is understanding (i.e., using ones intellect.)

And, whilst I agree with the principle that pfranz is stating, I think that the disctinction he makes is that between intelligence (or even intellect) and common sense. Working, as I do, among academics, one soon dicovers that the former is always present, but the latter is a rather rarer commodity.