For many years I carried a Gerber sharpening steel -- the one that looka like a glorified wood chisel. I lost mine under bad circunstances, but I was pleased to fing they are back in production. For just over 25.00 it is the most useul little thing I know of,

http://www.gerber-tools.com/Gerber-Sportsman-Honing-Steel-1372.htm