Apparently it's not only possible, but insanely easy to make Bose Einstein Condensates of photons. I'm not sure why you'd need a giant photon but apparently science can now make them. A single quantum mechanical photon is pretty much a laser, and those were pretty useful. Not that such things need to be useful to be awesome. Somehow a giant quantum mechanical equivalent of a photon is likely more useful than the quantum mechanical of a sodium atom.