That bugs me, but not as much as the hypercorrection of "you're" when "your" is the appropriate spelling. I see it all the time. Dumb kids know that the two are often confused and then apply one rule to every instance, as if they're trying to seem intelligent.

"Pick up you're stuff man."

i can't stand it when people confuse the "i" and "e" in certain words. "recieve", "wierd", "kieths". i mean, bad spelling usually makes me cringe, but this mistake in particular really makes me want to hurt someone.
This made me laugh. Especially since I spelled "weird" as "wierd" for the longest time. I honestly thought I had it right.