Two guys built these Space Marine costumes based on the Warhammer 40K tabletop miniatures game (http://us.games-workshop.com/games/40K/default.htm
). The game takes place 40,000 years in the future, when humans must be protected from both alien threats and themselves by genetically engineered super-warriors (called Space Marines) that wear power-armor.
The pair published a how-to guide in case you want to get in touch with your inner geek and build some Space Marine armor yourself: http://www.dremori.net/img/Guide.pdf
I'll warn you up front: these guys are nerdy and kinda annoying. Feel free to turn off the sound if their banter starts to bother you. The only thing of interest anyone says is that it took them 1 year to make the costumes at a cost of around either $200 or 200 Euros (it's not clear which).