Yes, they're fruits!

Photo by Matt Ball, 10/23/2012

These are fruits of the Common Cocklebur (Xanthium strumarium). If the barbs don't keep you away in the first place, please note that the seeds inside are highly toxic. Seriously.
DO NOT EVEN THINK ABOUT EATING THESE!  

But do think about this: What does a plant's DNA tell it to do? More tomorrow : -)