Cowboy Blob has one. SayUncle's building one. Alston wants one. Rock River builds a metal one. Bushmaster builds a plastic one. OlyArms builds one that eats out of Glock mags.
I wonder why the sudden flurry of interest?
Possibly the cold, wet background in the photo above is a clue: I'm gonna go shoot my rifle today. In the warm, dry, climate-controlled Great Indoors. :)