The military wants to be able to send soldiers up and over high walls, and sometimes grappling hooks aren't practical. What to do? Oh, I dunno, how about a vacuum backpack with suction gloves that'll let you climb up brick, glass, or pretty much whatever? Yep, that'll work.
Utah State University "Ascending Aggies" team recently won first prize out of 33 teams in the Air Force's contest to get four soldiers over a very tall wall. It's the lead climber that's the tricky part, see. The Ascending Aggies' solution was to build a PVAC, or Personal Vacuum Assisted Climber. It's frankly stunning how well that thing works.
Obviously, noise is something of a problem. And by that I mean it's louder that the shrieking banshees of hell. Not exactly stealth. But the team just got £65K from the US Air Force to continue development, so they're working on it. Business Insider has a full profile on the team and their device. Here's the video of them actually winning the contest, but if you want to see it you'll have to sit through music that is a crime against ears (even an elevator would puke). [Business Insider]