Well, I don't know how much luck you'll have trying to write one of somebody else's ideas, but all the little "how to get a story idea" things you can find online are made of plot cliches, so... How bout a couple good, old fashioned NaNo dares to get you started?

1. Open iTunes or whatever program you use to listen to music on your computer. Turn shuffle on. Hit the next button. Write a story based on the lyrics of whatever song plays.

2. I dare you to have a character who says, "That seems like something from a NaNo dare!" when something strange happens.

Bonus points if no one questions this.

Double bonus points if they say this every time something odd happens.

3. I dare you to write a story in which the main antagonist is completely nonviolent.

Bonus points if the MA is actively trying to take over the world, too.

Double bonus points if the protagonist is a pacifist, as well.

Triple bonus points if you work in a Wallace and Gromit reference in every chapter.

4. I dare you to have a character who finishes every sentence with, "...in accordance with the prophecy."

BP if it isn't fantasy or science fiction.

DBP if no one questions this.

5. I dare you to include a character who always knows what's going to happen next.

BP if no one believes them.

DBP if their prophecies come true, they point this out, and no one believes them.

TBP if the response to the psychic pointing out that they were right is, "You're making it up!"

QBP if the psychic character's name is River.

6. I dare you to have a character die in a freak trombone accident.

BP if this kickstarts the plot.

DBP if the character is the protagonist, and it STILL kickstarts the plot.

7. I dare you to make your main character a textbook.

BP if it talks.

DBP if no one questions this.

TBP if the textbook frequently puts people to sleep.

QBP if this is vital to the plot.

I'm done now.

Cool; you can definitely do that! :)