Memory sticks are the easiest way for the average person to transport significant amounts of data. Some people just email important information to themselves, but email has size limitations. Not to mention that sometimes you want to have that data in places without a reliable internet connection. Of course you can't beat a secure copy from one linux machine to another for data transfer, but I'm going to go out on a limb and guess that I'm one of the few regulars on this site who does that on any regular basis.
