A while ago, like in the fall, I went to get some dress shoes. While paying for the shoes, I found that I was one or two dollars short and was worried that I would have to go and come back a different time. The lady standing next to me saw my situation and paid the difference and I was able to get the shoes. I thanked her and she said that it's happened to her too and she knows how it feels.
I do that occasionally, and request from the recipient to pass on the favor one day to someone else and to ask of them to pass it on etc. Who knows how much good can come from one small good deed?
Now that is the ultimate act of kindness - helping out a lass in need of a new pair of shoes!! :)