Neuroscience: We Use Only 10% of Our Brains, True or False ?

I have not been able to track down the exact source of this myth, and I have never seen any scientific data to support it. According to the believers of this myth, if we used more of our brain, then we could perform super memory feats and have other fantastic mental abilities - maybe we could even move objects with a single thought. Again, I do not know of any data that would support any of this.