For my birthday I got a Nike+ from my fabulous roommate (and fellow runner) as a motivator to help me get through my runs while training for my 10k (2 weeks, yikes!).  I tested it out this weekend and loved it. I don't have the Nike+ special shoes but simply secured the sensor tightly in the laces of my shoes and I was ready to go (I do know they make holders that strap to your shoes - haven't had the chance to look yet).  You can set your workout for time, distance or calorie burn - which will be great for keeping things interesting in my workouts after my 10k (I get bored easily).  As you run you can just hit the center button on your iPod and it will tell you your distance, pace and calories burned.  I love the feature that allows you to choose a 'powersong' that can be chosen at the touch of a button for some added encouragement in that last mile, or up a tough hill. My current 'powersong' of choice - 'Disturbia' by Rihanna.