Have to add my nice biker story:
When I was in college and living at home, my parents left town for a week, so naturally I threw a huge party.

Now, I had some... interesting friends at that time, so I normally didn't judge a book by it's cover, but these bikers showed up at the party (friends of friends, who had told them about it). Three of them, older, HUGE, muscular, leather covered in studs... they looked very intimidating, but my friend said they were nice, they seemed nice, so I let them stay.
Fast forward to the end of the night. Everyone is leaving, the house is a mess. Four people stayed and helped me clean the place up a bit. My best friend, and guess who else?
Yup, the bikers.

Some of the sweetest guys I ever met.
I always try to keep an eye out for motorcycles on the road, and leave extra space if one is ahead of me, since they can come to a stop so much faster than a car can.