How do you find the exact center of a wooden dowel?

[Paschale]

I've been working on a few projects here for my nephew's birthday, coming up tomorrow.  I'm making a homemade lock for his tree fort door.  I make a latch out of wood, and now I'm making a temporary pin for it, until I have time to make a proper one.  What I'm using right now is a poplar 1 inch dowel and an oak drawer knob.  I made one already, and I had a dickens of a time finding the exact center of the dowel in order to drill a receiving hole for a screw.  (I'm using a two sided threaded screw/rod to attach the knob to the dowel).  It works fine, but it bugs me that it's off center. 

What technique do you guys use?  I had some ideas for some jigs, but I figure someone out there has figured out a very simple way to find the center of a dowel.   ???

[fstedy]

If you don't have a center finder take a framing square stand it verticle and lay your dowel on a flat surface measure up 1/2" on the  square and mark your 1" dowel, rotate a 1/4 turn make another mark rotate and mark another several times that should get you real close.

[low_48]

A way to drill the center of a dowel is to clamp a block of wood on the drill press table. Drill a hole so the dowel will slip in. Now you have the dowel set on the center of the drill press. If you don't have a drill press. Take a spade bit the size of your dowel. Drill a scrap of wood, but stop drilling just when the point comes out the back, not the outside diameter of the drill. Now you have a drill guide. Slip the block over the end of the dowel and drill through the small hole left from the spade bit point.

[barbender]

I think veritas makes a tool for finding center on round stock. I think you cradle the dowel in the square, and there is another arm coming off of the square at a 45 that bisects the dowel. so you mark it, turn the dowel 90 degrees and mark again. I wish I had a picture, it is pretty simple and a guy could throw something similar together. I just have a hard time explaining it.