For all that I try my best to spell check, for all that I try my best to remember basic grammar rules, I probably still, and will always look like a caveman bashing at a keyboard to someone somewhere. So, when I make mention here of some of the things that make my eye twitch, I'm fully aware that I'm guilty of some of the egregious sins that cause others to wince.
My biggest (minor) annoyances are when people use words that either don't exist or they use a word that to them maybe sounds similar to the word they're actually meaning to use, but it's the wrong word. I came to find out that the latter actually has a word! It's called catachresis or malapropism. And it drives me nuts. (Hey, I've started a sentence with "and." I knew I'd catch a sin here or there.) An example would be someone saying, "This is such flagrant food." I'd have to assume they meant flavorful, or even fragrant, but flagrant food? You've got me there, buddy, perhaps the food is shockingly noticeable.
Others include things already mentioned. (Loose/lose. You're/Your. etc.)
Lastly, I think that some people might find this David Mitchell Soapbox amusing, and appropriate!: http://www.youtube.com/watch?v=kge9ZzjsfW8&feature=plcp
*The usual warnings apply. It's a YouTube page, so there may be swearing or inappropriate items on the page. The rant, however, is remarkably free from such things.*