eggcorns

The Eggcorn Database

This site collects unusual spellings of a particular kind, which have come to be called eggcorns. Typical examples include free reign (instead of free rein) or hone in on (instead of home in on), and many more or less common reshapings of words and expressions: a word or part of a word is semantically reanalyzed, and the spelling reflects the new interpretation.

Interesting stuff. The one that's surprised me most, so far, is "be who of" (that is, what "behoove" becomes in the mouths of the confused).

resource for researching vehicle fuel efficiencies

GreenerCars.com

Has some pretty in-depth analysis, although the free website doesn't make it as clear as I'd like how the quantitative aspects work exactly. I'm disappointed that it doesn't say much about diesels, but their reasoning for doing so is reasonable.