I know that this is a constant ocurrance in the computer field. Every time you go out and buy a larger disc storage ccapability, a few weeks later you find that you could have bought more storage space for les than you originally did. And this sort of thing is going to keep on happening as long as I am involved in Information Technology (IT) at my office. What I would like to know is do you have a rule of thumb about how quickly you upgrade? Desktop PCs I never look for an upgrade until atleast four years latter and my current desktop is one year old. What is your rule of thumb for portable data storage?