Welcome to WebmasterWorld Guest from 188.8.131.52
During initial tests, advertisers who mainly used phrase and exact match found that adding modified broad match keywords increased campaign clicks and conversions, while providing more precise control than with broad match.
you mean by misspelling widget as wiget? just a guess, but i'd say G would have a difficult time understanding what this word means, so there'd be few synonyms, and it wouldn't ever do much triggering.
but if you spelled widget correctly, i bet it'd sweep up anyone who typed it incorrectly.