Row Counter tool. You'll want this.

Look at this cool row counter that Susan Bates sent me.  You wear it on your finger (it's very comfortable) and you click the big button every time you complete a row. You push the small button to start over at zero.

I like it!  And it's under $5. Sometimes when I am running, I run laps around the park... and I get lost in thought and forget how many laps I have run.  I could wear this for running too!  I love it when my worlds collide.

How do you keep track of your rows when crocheting?