At Willy -home of the spellinggods- you can read about Common Errors in English.

What is an error in English?
The concept of language errors is a fuzzy one. I’ll leave to linguists the technical definitions. Here we’re concerned only with deviations from the standard use of English as judged by sophisticated users such as professional writers, editors, teachers, and literate executives and personnel officers. The aim of this site is to help you avoid low grades, lost employment opportunities, lost business, and titters of amusement at the way you write or speak.

Note: site at port 8080, if you are behind a proxy or strict firewall, you will not be able to visit the site.

At broken-notebook.com you can see some very fancy use of [AJAX], checkout this spelling checker, make some mistakes and see how it works. AJAX all the way!

Yeah why not.

Mijn dochter (6) kan googele.

Nee niet goochelen, ze kan bepaalde spelletjes op internet vinden via Google.

(in de woonkamer, your classic non-tech parental control)

Maar als je zes en blond ;-) bent en voor je leeftijd verdraaid goed/creatief met taal bent, dan staat er dus gewoon 'Gogele'. :-)

An incomplete list of words having differing meanings in standard British and American English. Lots of fun words. For example: "brew", in the UK "cup of tea", in the USoA "beer". "I would like a brew with my breakfast"?

At
Juicy Studio you can do a "Readability Test"

Gunning Fog, Flesch Reading Ease, and Flesch-Kincaid are reading level algorithms that can be helpful in determining how readable your content is. Reading level algorithms only provide a rough guide, as they tend to reward short sentences made up of short words. Whilst they're rough guides, they can give a useful indication as to whether you've pitched your content at the right level for your intended audience.

And quess what, Willy has a rank of 8, 8 - 10 Most popular novels.