Originally Posted By: wfaulk
The old man the boat.

Oh, that's a good one, which I hadn't seen before. And unlike most such non-forward-parsable sentences, it can't be fixed with commas, hyphens, "which", or "that". Fortunately, unlike the others, it relies on two ambiguous words (common-adjective/rare-noun and common-noun/rare-verb) and so that case probably doesn't very often crop up accidentally.

Peter