|GE Hadiman - Source: Adifruit Industries|
|HAL - Source: Cyberdyne|
Panasonic's Powerloader Light, for example, helps the user carry an extra 88 lbs and shifts weight as needed to counteract the walking motion. (Source: Hightech)
Last but most certainly not least, DARPA has been funding the development of this technology for military use since at least 2001. And for those of you who don't know what DARPA is... well, you're just not paranoid enough and beyond my help.
As of 2010, it was down to Raytheon's OXS 2 and Lockheed's HULC super-soldier suits. With these suits, soldiers can walk or run for hours, carry loads up to 200 lbs effortlessly, and lift up to 500 lbs or more without breaking a sweat. (Sources: Popular Science, Hightech-Edge)
So, there is my little geek trip. I haven't had a to use this in one of my stories because I mostly write far future stories where unmanned military technology reigns.