One of the benefits of having an organized stash is that you can find (and use) yarn that's leftover from other projects. But what do you do if part of the ball has been used? How can you tell how much is left in the ball?
One higher-tech answer is to use some sort of meter that you'd thread the yarn on the way to a ball winder. By the time you finished re-winding the yarn, you'd know just how much yarn you had to work with.
Such a meter is sold through some knitting catalogs and I was tempted to buy one, though I balked at the $50 price tag. I mentioned it to Rachel, a wonderful employee of my local LYS, Knitorious, and she told me that she had purchased one, but that she learned that it was actually designed to measure fishing wire. That's okay, except that it actually damaged the yarn. She even offered to give me hers, but I declined, for obvious reasons. I don't want to damage my yarn.
But there's hope. Rachel told me about a website for a DIY yardage counter. Check it out. It doesn't look too hard to do. When I have some time and the help of my handy friend Sally, I'm going to make one. And I'll report back here.
I was mentioning this to a knitting friend, who pointed out another solution, one much more low-tech and apparently something people who sew know all about. Just measure the distance from the tip of your nose to the tip of your outstretched fingers when your arm is held all the way out to your side. Then, hold your yarn between your thumb and forefinger on your right hand and hold it at your nose with your other hand. Stretch out your right hand (as you did when you made the initial measurement), letting the yarn glide through the fingers of your left hand. Repeat. See how many times you can do that with your ball of yarn and add it all together.