Can't think of anything that sounds impressive and fits in 2 sentences?

Absolutely not. But linguistics seems like a legitimate enough field, and Chomsky is considered rather influential there.

His work seems to follow logically from Wittgenstein's point that a lot of philosophy comes down to the precise meanings of words.

So you're just going by his reputation? I have read about some of his ideas and formed the opinion that they are bad (apart from the one i mentioned).

Ignore his politics, though I personally have a great deal of respect for people with extreme politics.

The Chomsky hierarchy -- a method of classifying formal grammars. Seems computer science-y enough that you'll consider it as something real. http://en.wikipedia.org/wiki/Chomsky_hierarchy