This is a handle / blade holder for matte style blades, turning them into less dangerous and mostly useful 3D printer build platform scrapers.
I have a bunch of replacement blades for my razor (what I've called an X-Acto knife up until now :), and I had begun using one as a "scraper" for getting things off the build platform of my Ultimaker. Like Suavepotato mentioned in his description of "Razor Blade Holder and Scraper", "I do not like using a naked blade." (http://www.thingiverse.com/thing:3090)
Update: I've added a "guard" perimeter around the blade as nostarman suggested, and made the base of the handle rounded and IMO more aesthetically pleasing.