Eggcorns are words that are misspelled but somehow in their misspelling seem to get deeper into the heart of the word than the correct spelling. Geoffrey Pullum coined the word and now they are even collected in databases: http://eggcorns.lascribe.net/
An eggcorn is not another name for malapropism. The mistake must make more sense than the original, like "for all intensive purposes" and "like a bowl in a china shop."
Psychology Today (March/April 2006) had a few other great examples...
- Whoa is me
- Spurt of the moment
- For all intensive purposes
- Girdle one's loins
- Far-gone conclusion
- Zero-sum gain
- Works like a champ
- Take with a grain assault
- Southern brawl
