A small ceramic rod sharpener.

[wsdstan]

I have a habit of buying stuff related to knife sharpening when I see it.  Gun Shows, flea markets, Ebay, and yard sales.  Here is one I got a few months ago.  While I have two other ceramic sharpeners this one is really small and has a great storage function.  It is a good sharpener too with two different angles. 

Made by Lansky it is called a Turn Box Sharpener.  Works like all of them, just pick your angle and hold the knife plumb while you draw it down the rod.

[randyt]

looks like a good option. I've been dabbling with diamond "paddles" of different grits. However when the day is done I gravitate back to a stone.
I picked up a "puck" from barynox and it's been great.

[wsdstan]

I have a lot of stones and diamond guided hones and three other ceramic sticks. For the money the little Lansky is hard to beat.  With the two different grits it repairs blades well and touch ups are easy.  I am one of those people who has trouble holding a consistent angle so the sticks help me avoid that.