The semicolon is not used enough; the comma is overused.

I couldn't agree more with Erin McKean, editor and lexicographer of the New Oxford American Dictionary, and "dictionary evangalist" who has designed Semicolon Appreciation Society T-Shirts in response to recent discussion in the New York Times. I may not purchase the T-Shirt but I have already ordered the stickers so I can correct signs on the street and insert a semicolon where one should be. No, seriously.

If you love dictionaries, find an hour to listen to Erin's presentation to Google on ten things she wishes people knew about dictionaries.