The Garmin Forerunner 305 is getting a little long in the tooth. However, it still performs flawlessly. It will allow you to train by heart rate and pace. This really allowed for me make many breakthroughs on the run. It also has the ‘virtual nemeses’ – this guy will push you!
The Garmin Forerunner 310XT is the new – bigger, better, faster forerunner. It adds longer battery life, the capability to link with ANT+ power meters (SRM, power tap, etc), fully water proof. It is rumored that a new Forerunner is coming out in the spring 2011.
The speed / cadence sensor allows for you to record and display speed and cadence. In addition, now you can record your indoor trainer sessions.