Google really is rather clever, isn’t it. As a jape I used the “word”, umberleevabull in a chat to a friend. Try a search on that word and Google recognises that you really meant unbelievable: Google Search: umberleevabull.
Unburleaverbull!
(Doesn’t recognise that one though, hah!)
Footnote: Actually, it now does recognize that last spelling and once again suggests Unbelievable. I presume they have some sort of algo in place that automatically updates the database when someone uses the misspelled word and lets Google correct them. Very, very clever.