Word Pet Peeves

Here are some of the mistakes I've come across in professional writing:

Should of and could of instead of "should have" and "could have" (or "should've" and "could've"). ("Of" is correct in "kind of", however.)

(Spotted today, 12/4/06) "Lightening rod" should've been "lightning rod" (unless the rod somehow reduces the weight of things.)

"Alter" instead of "altar" as in "returning to the alter".

Confusion of "their", "there", and "they're" -- I do this often too, but their is really no excuse for they're mistakes on this -- there supposedly professionals, right?

Then there are "your" and "you're". Oddly, "yore" is almost never confused with either.

Using apostrophe-s for plural's.

Favorite pun of the day: "it takes me back to Kerry in ’04 when he tried to convince gun owners and hunters that he’s a Nimrod."

(Another one spotted today, 12/4/06) "Standing up to" used in the context of "supporting"; it should've been, "standing up for".