So, on my way to and from work every day, I see a Trek 4300 chained up to a post, but I noticed one day that his quick release mechanism is being used like a wing-nut. That was about 2 months ago.

Would you just mind your own business and let him/her be?

I've been thinking of printing out instructions from park tool's website on how to install a wheel properly, and attach them to his handlebar so he'll read them.

I would hate to see what would happen if his front wheel came off as he was going 20mph...

I'd do exactly what you suggested. If you save the person's life, it's worth the chance of offending them. Make sure you attach a hand-written note to the back of the instructions politely telling them why you're giving them the page.

yeah, lunch time tomorrow, i think i'll do that... i'll post an update and see if he/she will change their dangerours ways...

For my curiosity, how can you tell just walking by the bike that the quick release is done improperly??

Huh......Ive always used my quick release like a wing nut. Educate me in its proper use.

He saw that the curved concave side was facing outwards instead of inwards. In the open position, a lot of inexperienced people will just grab the lever and spin it around to tighten. Getting it as tight as possible by spinning it will result in only about 5-10% of the clamping force necessary. The proper procedure is to flip the lever laterally (instead of rotate) so that the concave side of the lever faces inwards.

one side says 'close' and one says 'open', if you can see the word 'open', then its wrong

OK, that makes sense, thanks, I guess I've just never seen them done wrong (or at least never noticed it)

Sounds like a very good deed!! Somewhere, a facial reconstruction surgeon is cursing you for it