This really only applies to OS 10.4 and earlier, but on my work mac I have a lot of applications which I use only intermittently and hate them cluttering up the dock, especially programs I launch once a week instead of every day. I know I can have the applications folder on the dock, but there's too much scrolling involved in that, so I made a folder and put aliases to all my programs that I don't use a daily basis to help keep clutter on my dock to a minimum. Fiendishly easy. Works nicely. Yay.