Cool idea.
I saw a similar idea on a jeep forum a while back. Someone had taken a leaking can, make a cut just up from the bottom, a matching cut down from the top, then cut along the seams. Then they put in a piano hinge on one of the seam lines and installed a hasp on the other end. they would pack it with tools for use on the trail.
Other ideas from the forum included keeping a CO2 bottle in it, speakers and stereo, .... I've thought about making one but don't want to buy a new one to cut up.
I actually went to the other forum and found the thread but the pictures are no longer accessible. A quick search on Yahoo shows several web sites selling the same one.