Learn from fixes others have made
There are some tools which just correct someone's list of commonly misspelled and corrected words.
@jsoref has hundreds of repositories worth of corrections. It would be nice to try to perform some heuristic / analysis / machine learning / insert buzzword here in order to develop a common list of suggested fixes.
This is obviously appealing, but it's not something I'm likely to work on anytime soon. I'd be interested in talking w/ someone about implementing something in this area.