One of the most unobtrusive fitness trackers available is the new Nike+ Fuelband ($149), which fits around your wrist. The Fuelband measures time, calories burned and steps taken to calculate an overall activity score that displays on the wristband. The water-resistant band uses a wireless Bluetooth connection to link to smartphone applications. There’s also a USB connection for linking to a computer, so you can record results over a long period of time. nikeinc.com.