Nanook
F-notso-NG-anymore
Or you could rig up some 1x2 in a frame and string a bunch of window screen across it. The frame lays down and with enough slack in the mesh, prevents the brass from "trampoline-ing" across the lawn.
I saw the other day on the A&E show, The First 48 where some guy(if you know the show, you know these are not the best people around) attached a wal-mart bag to his glock and made himself a shell catcher. used for all of the wrong reasons, but the guy was innovative