Off the Cuff Measurements
These items are definitely productivity related, because you can't manage what you don't measure. At the Shana Logic site they're selling some interesting accessories, and I like this stainless steel bracelet with rulers in metric and inches.
They also make compass earrings, a level necklace and a thermometer necklace, so you'll be able to stay on course and get things done. I'd make a pun for each item, but will leave that for you to enjoy on your own.