I have been using Mileage Manager for the past year.  I find it to be a very convenient and inexpensive way to manage my airline, hotel, credit card and car rental miles in 1 place.  It is very simple to use.  You simply add the user name and password for each frequent flyer program you belong to.  It then gives you a summary of all your frequent flyer programs as well as the points needed to get to the next status level.  They also alert you of mileage bonuses.