A friend of mine got a replica of an AK-47 it´s fascinating. But these here are awesome! "Fully" functional models of various guns built from Lego. You can either order kits with all required parts or just the construction manual for various discontinued models. I found this linked from a link on nerdcore, where you can read a story about a guy having a visit from a swat team for assembling the "gun" in his office. My favorite is the Semi Auto, so if want want to give me a nice christmas present...