Go GoKey

Francesca and my ex-neighborhood neighbor Cristina launched their kickstarter project, it's a little bracelet that allows you to safely carry your key while being on the run.
Also on Fast.Co here: http://www.fastcodesign.com/1669495/gokey-the-easiest-way-to-store-a-key-when-you-run

And your's truly is responsible for most of the imagery and the videography in the later half of the video.

Good Luck!