The one that's been driving me crazy lately: 4 as a synonym for "for." I understand some percent of the population "rites lik dis 4 serch" -- but I certainly don't! When 4 = for, and "for" is on every page on the internet, it almost had me pulling my hair out.
Here's an example (but not my exact query). "iPhone 4" will match pages with "iPhone" and "for."
It should be easy enough to write an extension or even a bookmarklet for this. You just have to add &tbs=li:1 to the end of the URL to enable "verbatim" mode.
Fantastic! That’s one of the things that has been bothering me on Google lately.