I ran across one today, [by enlarge](http://jeremiahgrossman.blogspot.com/2006/09/csrf-sleeping-giant.html) instead of [by and large](http://www.straightdope.com/mailbag/mbylarge.html). This ranks right up there with [for all intensive purposes](http://eggcorns.lascribe.net/english/32/intensive-purposes/).