I use google as a spell checker.

For example I just decided that the game theory solution concept was
Stackelberg equilibrium (9,290 hits) not stackleberg equilibrium (341 hits all from people who don't use Google as a spell checker).

Brad Delong is a big fan of google, but I suspect that this is one use he does not make of it. I recall that back when he had a 5 Mb hard disk, he deleted the spell checker to save space.