Leather Strop

2" wide with an 18" long surface.  Leather is 6-7oz.  I think a strop is the number one way to keep a knife sharp, and it lengthens the life of your knife by not having to go to a stone every time you need a bit of touch up on the edge.  Strops are a standard with straight razor guys for a reason.  Stropping a knife will get you the best edge and is very easy to do.