I can't think of a more useful tool for tracking all my differenet points, miles, rewards etc Awardwallet.com tracks your frequent flyer miles for airlines, hotels, rental cars, restaurants, and many other companies all on one website. Been using on my PC for about a year now and am very happy with it. I'm surprised at how many types of accounts they support... just about anything you can think of.
It made my day when they released an iPhone App so I nolonger have to rely on being at my PC to check status etc!