This is the information age, so your bike's computer should be, ahem, up to speed. Bontrager's next-generation Node 2 Digital Computer lets you train smarter with speed, cadence, programmable heart rate zones, wattage and even a nutrition reminder on one easy to read screen so you don't have to play with buttons while you ride. You've also get altitude and a percentage grade. Node computers can receive data from 3rd party power devices that are ANT+ compatible like SRM cranks and PowerTap hubs, too. The water-resistant casing lets you ride all year long and the included soft-strap heart rate monitor keeps an eye on your training.
Fits on most handlebars and stems.
Node computers require ANT+ sensors (sold separately).