This is how I keep track of all my runs...
This is the Nike+ iPod Sport Kit. It is what has motivated me to get out and run. Simply attach the Nike+ sensor onto your shoe, then plug the receiver into your iPod and you will hear feedback about the distance, time, pace and calories burned directly through your headphones. Afterwards a performance summary appears on your iPod screen and can be heard through the headphones. THEN you plug your iPod into your computer and NIKE downloads your run information to their website. Genius! So convenient. The Nike+ sensor is waterproof, virtually unbreakable and costs about $29.00.
**Please note that this sensor is most accurate in a NIKE shoe which has a built in pouch in the sole of the shoe. I wear Brooks running shoe so I strap it to the laces. It is about a tenth of a mile off every mile for me, but I know that so I make adjustments accordingly. If I want to run3 miles I run 3.3, if I want to run 8 miles I run 8.8, and so on.