A software solution to a hardware problem
External mouse and keyboard can, of course, be plugged to your netbook but this would mean having to deal with hardware switches, cables or, in case of wireless devices, Bluetooth configurations every time you switch between your desktop and your netbook computer.
Here comes Synergy: a simple utility that lets you use your desktop computer's mouse and keyboard to control your netbook without the need of any extra hardware but a network connection, in the most intuitive way by simply moving your mouse pointer off one side of the screen like you were using a single computer with two displays.