What "prompts" you?

Sometimes I sit down at my keyboard and wonder what the heck I'm going to write about.  This seems to happen to a lot of writers as there are a plethora of writing prompt sites across the internet.  Anything from plot and character prompts to three word prompts to photo prompts.  I've used prompt sites in the past when struggling during NaNoWriMo.  Desperate to use any tool to get that flow of words going again.  One year, I used song lyrics to prompt me on my month long journey.  A lot of times, as I mentioned previously, I use strong emotions to prompt a story.  Getting those feelings down on paper and developing a character out of those feelings along the way.  Very rarely, I'll remember a tidbit of a dream and those brief images prompt a story idea.

Writing prompts often serve to breathe new life into a story or get a new story idea off the ground.  What prompts you to write a story?  What tools do you use to get the story going again when you get stuck?