Anyone who knows me probably knows that I'm a grammar freak. I'm not saying my grammar is perfect; it's nowhere close. But I have many pet peeves regarding common mistakes with the English language.
Scott Hanselman blogged about some one-page reference sites, including a link to this link to a site listing common errors made with the English language. Although it's not the prettiest of sites, I like it a lot and I marked it as a favorite.