If you are a heavy Command Prompt (DOS) user, this might well be a very useful tip. In the DOS prompt, the most commonly used command would be cd (change directory) to switch between directories that you work. If you working between more than one directory (say C:\Documents and Settings\username\desktop) and (say C:\Windows\system32) then everytime you change between direcories using the cd command, you need to type in the path as well (atleast I feel its not friendly).
Well here is a solution, Windows has the PUSHD & POPD DOS commands that help you navigating between these directories. PUSHD/POPD are great tools when navigating between directories and shares temporarily. PUSHD & POPD commands are the unix equivalents which can remember the directories that you navigate in the memory as Last IN First Out (LIFO). So, when you navigate between multiple directories and then need to comeback one step or two, you can simply comeback using one single command.