A couple weeks ago I was flying from somewhere to somewhere (can't keep track anymore, but I may have been going to MEM, or FFL, or GSO). There was a very tall man in a wheel chair who was moving slowly with a cane. The FA said to him, "Your seat, 10D, is right over there, but I'm a little worried about whether your feet are going to fit because with the bulkhead, there's not a lot of room." With that, I asked the woman in 2C if she would mind sliding over and I went to 10D.
The upshot: Nobody was in 10E, so I had the row to myself, I'm short and don't need the leg room and I got all the free drinks/Twix/Bananas I could use. Plus, a woman gave me a hug because she thought it was such a nice thing to do! The man thanked me over and over on my way off the plane. (He remained seated.) He told me that he had never flown in F before and it was such a thrill.
Another time, the woman sitting next to me in F gave her seat to a soldier. He was a very nice guy on his way home from Iraq. He was supposed to be going to base for a week or so, then on to home to see his wife and daughter. They were at the airport waiting for him past security. OK, I'm crying again remembering it.