I got a great little gadget from Castillo Leather goods some time ago. Works great. Keeps the chalk OUTSIDE of my cue case. And, very reasonably priced. He sells em on his web site, eBAy and here:
Plain leather holders: http://forums.azbilliards.com/showthread.php?t=166261
Exotic lizard leather holders: http://forums.azbilliards.com/showthread.php?t=172478
Plain leather holders: http://forums.azbilliards.com/showthread.php?t=166261
Exotic lizard leather holders: http://forums.azbilliards.com/showthread.php?t=172478