Wikipedia, A Source Of Error Corpora

They guys from Morfologik have created a neat method for gathering error corpora.

They've succinctly described why such data sources are needed:

Background. The developers of grammar checkers, and autocorrect lists, have hard times with finding relevant corpora. Revision history is an excellent source about native speakers perception of linguistic norms. Frequently revised typos are perceived as errors that need to be corrected, so using these typos on autocorrect lists is justified. The same goes for style, grammar and usage errors.

Well, where is the biggest source of revision history on the planet? Wikipedia. You can read the whole post on the Morfologik blog.