Where do you get your ideas for characters?

I saw a really interesting story on NPR yesterday, about a performance artist who develops characters from grocery lists. Hillary Carlip hunts for discarded lists, and then — based on clues such as what the list contains, what it is written on, and the handwriting — she creates a character sketch of each. She also goes a step further, though, dressing up as these characters (and boy does she look believeable!).

I'll definitely be checking out (her pun, not mine) the book, a la Cart, but this story made me think of how fiction writers — myself included — get ideas for characters. I know that I am fascinated with people, and often draw entire characters from short glimpses of strangers on the street. People-watching for character ideas isn't a new concept... but grocery lists?

How do you get ideas for your characters?