I've always cried easily and I probably always will. I got choked up just reading this thread. I cry at the end of every movie - yes, even goofy comedies like Wedding Crashers. In fact, come to think of it, I think I sometimes cry more easily at happy/touching things than at the sad ones. Like the Sarah McLachlan/abused animals ad mentioned above - it just depresses me and makes me cross at the evil people who are irresponsible with animals so I'm more disgusted than weepy.
Once my tiny niece - about 3 years old - went running up to some boys at the beach, wanting to play with them. She was all smiles and giggles and gave them some of her precious shells: couldn't imagine anything but them wanting to play with her. Instead, they - at the ripe old age of about 5 years old - were annoyed that "this baby" wanted to join them so they ran away and shouted, "LEAVE US ALONE - You're ruining our game!" . At first she chased them delightedly thinking that they were playing tag with her, and then they just stomped off, while she stood there blinking, not comprehending. I swear, I bawled for about 2 days after that. She's now 9 years old but even as I type this, I'm crying remembering it. *sob*