this is copied from the original posting i did on the about.com motorcycles forums - i've had such a great response to it over the last year that i thought i'd post it somewhere easier for me to find for copying and pasting  

for those who are going to be taking friends and family out for a ride, i have put together a list of points that i think every new passenger should be informed about before the ride starts, and experienced passengers should be reminded of now and again. this is a list i go through with every person that rides on the back of my bike, and if they disagree with any of the points, they don't ride with me. simple as that.

1. you will wear a helmet (required by law anyway), sturdy footwear, eye protection, full length pants (i have spare chaps if you're in shorts), and preferably gloves. tanker and i have many helmets of different sizes, lots of pairs of gloves, a few pairs of jeans, a spare pair of chaps, and lots of sturdy jackets for our guests. never assume that someone who doesn't ride has appropriate gear!

2. you will keep your hands on my hips or waist at all times. this allows me to ensure you're still with me, and by your grip on me i can get a pretty accurate idea of how you're doing. removing one hand temporarily to adjust your helmet or glasses is ok, but other than that get a grip!

3. you will keep your feet on the pegs, and not fidget, when we are stopped for any reason.

4. you will inform me if you have to make any adjustment to your position, such that i can be prepared for the shift of your weight (i weigh +/-150lbs, and my passengers often outweigh me by 30lbs or more).

5. you will follow my motion when we are in a curve or turn. you can either follow your reflection in the back of my helmet, or look over the shoulder that is on the side we are turning towards. you will not try to fight the lean of the bike, or try to initiate the lean, or i will stop and ask you to get off. you've got legs - you can walk home.

6. you will tap me 3 times on the back of my helmet if you need to stop. this is only to be used in emergencies, like your leg fell off, you're having a heart attack, etc. you can yell in my ear to tell me you need to use the bathroom, but if you're missing a limb, i'd like to know immediately!

7. you will have fun! it's mandatory! :)

feel free to add, delete, divide, and multiply at will. i've worked this down to about a 45 second speech, and it seems to be relatively easy to follow for everyone. i haven't had to boot anyone off yet, and have had great times giving my friends miles of smiles.