The easiest and one of the safest ways to hide something for a longer time (like, say you're going to a LAN and you have files you don't want to let people access), add them all to a passworded zip archive and delete the original files on your HD. Later, you can just pack them back up again, or view them unzip them one by one.

"Stephen Wolfram is the creator of Mathematica and is widely regarded as the most important innovator in scientific and technical computing today." - Stephen Wolfram