1. An Apprehensive Employee Is a Good Employee

Researchers at Rice University have found that being in a bad mood may actually spur creativity. Professors Jennifer George and Jing Zhou collected data from 67 employees at a helicopter manufacturer, and they found that when workers were happy, excited, or enthusiastic, they were sometimes overly confident about the work they had done. In contrast, people who felt uneasy, distressed, or mildly fearful were critical of their own performance and thus more motivated to come up with new ideas. "If you're working on a creative task, you have to decide for yourself when you've done enough," says George. "People often use their mood as input into those kinds of judgments."

2. Serving a Captive Audience

Headphones are headphones, right? Not in prison. Koss, the Milwaukee-based maker of audio headphones, has designed a model specifically for use behind bars. They are made from clear plastic so that prisoners can't hide drugs or other contraband in them, and they include fewer metal parts that can be fashioned into weapons. The cord is also special, designed to snap in the event someone tries to strangle another person with it. Both the prison population and Koss's sales hit all-time highs this year.

3. Migraine Relief for Your Teeth

Dr. James Boyd, a dentist and migraine sufferer, has come up with a mouth guard designed to alleviate painful headaches. Boyd calls the FDA-approved device the NTI (for nociceptive trigeminal inhibition system). It is small, covering just the two front teeth, and designed to keep the jaw from clenching while the wearer sleeps. In clinical trials, more than 80% of patients felt some relief after using the NTI for two months. It costs around $500 and is available by prescription from a dentist.

4. A Chair That's Got Your Back

A funny-looking seat with 11 fake "vertebrae" running up its spine recently won an award from Design Journal. The Verte ergonomic office chair adjusts in three dimensions, moves with you as you bend, and sports a thick foam seat and headrest. Manufacturer RFM Preferred Seating in Hillsboro, Oreg., says that the $1,995 chair, which a chiropractor dreamed up, moves in sync with you as you shift and remembers the contours of your spine -- thus easing back pain and improving posture over time.

5. Reinventing the PC Keyboard

So long, QWERTY! The FrogPad keyboard has just 20 keys and repositions the most commonly stroked letters so that you can type with only one hand. The device is tailor-made for designers, architects, and others who often handle a mouse or other instrument while typing. The board is also helpful to anyone with an injured or disabled hand. It is the size of an index card, weighs only 4.9 ounces, and links with Macs, PCs, and most mobile phones and PDAs. The price ranges from $150 to $225.