Papercraft Metal Gear Rex made (a few months ago) from designs I found, well, on dA actually
Excuse my American, but 'tis AWESOME!! Unfortunately this particular REX's railgun got a bit damaged in a drunken 'omg check out paper rex!' moment, and the ensuing drunken attept at glueing it back together.
Also, photo editing fun
The whole thing is nearly 10cm tal, the railgun is about 18cm long! As far as I can tell the designs are from a pre-mgs3 gift pack for some games convention (maybe E3?) where there were instructions for this, and also the (then unknown) shagohold.