If you've been riding your bike around town, yet finding yourself completely stupefied when you need to make directional decisions, perhaps you need to check into Garmin's latest cycle-friendly GPS boxes -- the Edge 605 and 705. The latter -- which is the company's higher-end bike-mountable unit -- comes crammed with a slew of features aimed at cycling enthusiasts hoping to get more out of their workout, including automatic speed, distance, time, calories burned, altitude, climb, and descent tracking, plus the ability to review the recorded data. The 705 also has an array of add-ons that further assist the obsessed dedicated rider to suss out his or her performance levels, including a heart rate monitor and a speed / cadence sensor. The lower-priced Edge 605 takes a slightly less hardcore approach, though still delivers on skill-testing functions like "Virtual Partner," which allows you to "race" a ghost-competitor over a specified distance and speed, and "Courses," which lets you make a rival out of yourself by clocking your performance against a previously recorded run. Both devices will make an appearance in December, with the 705 ranging in price from $499.99 to $649.99 (depending on the configuration) and the 605 will be $399.99.