Many of OS X's files as well as folders are unseen when functioning with the system--most of the Unix-only folders, for example /usr, /etc, and /bin, for instance. If you want to always make out these hidden files plus folders, you can do currently that.

Most of the moment, although, I don't want to observe hidden files, as I don't do much with them. I actually only want to observe them when I wish to open one of them--for editing in a text editor, for example. For those circumstances, Snow Leopard offers a new solution to the hidden file dilemma: the ability to see hidden files quickly, but only in Open and Save dialogs.

In numerous Open or else Save dialog in Snow Leopard, only press Shift-Command-Period to show unseen files as well as folders. This command is a toggle; unseen files will be revealed as you navigate through different directories in the Open or else Save dialog.

To conceal the unseen files again, only press Shift-Command-Period again. The setting is temporary, though--hidden files will always be unseen when the Open or Save dialog emerges onscreen. (To some extent clearly, this also only works if you've clicked the triangular key to enlarge the dialogs to explain the folder browser.)