Yes Please!: Water Powered Jetpacks
I want one. Yesterday. Ooh, and a firetruck to power it. That way when I have children I can tell them, "Children, in the golden age before you were born daddy used to ride a water-powered jetpack to the liquor store. Now he drives a minivan. Someday you will understand the sacrifices he's made for you. And also, be daddy's designated driver.
Thanks to Digital Mulch, landscaping the interwebs for over 10 years.