I have two BLF GT Flashlights soon to be on the way. First thought as many others, how to carry and protect it. Lots of others have mentioned different bags and cases. Things like tool boxes, camera lens cases, etc.
I'm a Do-It-Yourself type, and first thing come to mind is, make one. Here's my idea.
1 piece - 6" PVC pipe cut to desired length.
2 - 6" PVC end caps. One, slip on or glue in place. The other, plan to do a little carving to for placement of a hinge on one side, and a hasp to keep it closed. Shims, radius to circumference so the hinge and hasp have "flats" to attach. Epoxy the shims to the pipe. (Or I suppose you could always get a 6" threaded adapter, and threaded cap and screw it closed <<--UGLY)
Line the interior of the pipe with (slab) high density close-cell foam. Pipe and caps.
Paint it? I probably will.
Add a carry strap and the necessary hardware to attach, done.
If you wanted to get creative, cut the pipe in half equally for length, and make it like a tool box.
If you have other ideas for a case or bag for the BLF GT, share them.
I did a search and found this after posting. http://www.instructables.com/id/Tough-PVC-Cases-For-Anything/Tough PVC Cases For Anything