Desktop sharing is basically when you can view another computer's desktop and control it over the internet. If you are like me where everyone needs your assistance, this program will be very handy indeed. Whether grandma needs help or if you are in college, this is a lifesaver.
Go to http://www.teamviewer.com/download/index.aspx and download the version for the type of computer you are using. You will get the full version, the other person you will be helping out can get either the full or the QuickSupport version of the software. If at one point you think you will be using their computer to help someone out or if you think they will, they should get the full version.