We asked lots of people to take our picture while we were on our honeymoon and no one said no - they were some of our best pictures.

We received some CM pixie dust as well, but I can't recall anything else specific from another guest. We were there in August 2006 during free dining, and it was very hot and crowded and most guests didn't seem too particularly friendly toward each other.
We did also take pictures for those who asked, and also gave away our Fastpasses to Expedition Everest as we decided to leave the park for the day to a mom and son - they seemed really excited!
My husband and I also always offered up our seat on the bus to those who would otherwise have to stand and who looked like they needed it more than we did - a parent with a child, an elderly person, or someone who just looked like they had a rough day. Ironically, it was that particular act of kindness that left a bad taste in my mouth. One night leaving MK, a mom with a toddler got on the bus and all the seats were full. My husband immediately stood up and said, "Here, would you like my seat?" The woman didn't answer him, but just plopped right into the seat as though she was entitled to it and he shouldn't have been sitting there to begin with. No thank you, no smile, didn't even make eye contact with him, and in fact shoved her toddler off onto the floor. Someone else nearby even looked at me like, "Wow." We were tired too, so it affected me more than it should have, and I was so upset at someone not responding with common courtesy to something like that. It made me want to tell my husband to keep his seat in the future, but I know most people aren't like that and he'll always give it up anyway. It'd been a long day and it was all I could do to bite my tongue - I wanted to say, "You know, it's polite to thank someone who does something nice for you. Have a magical rest of your trip."
We're going back this mid-August, but I don't think free dining will be going on at that time, so I'm crossing my fingers for a little less crowded and lots of friendly/polite other guests.

This is a great thread - after the thread about character dining, it's heartening to see so many people doing nice things for each other.