Mac OS X: Users coming from Windows PCs are accustomed to desktop shortcuts, but it's not something that's seen often on a Mac. Fact is, you can make a shortcut for just about anything in OS X with just a couple of mouse clicks. They're just not called shortcuts, they're called aliases.
To make an alias, just right-click on the app, file, or folder that you want to have a shortcut. When the menu shows up, just click on the option to "Make Alias". A new file will show up that looks just like the old one, except it has the word "alias" at the end of its name. If you look closely enough, you'll also see a tiny little arrow in the lower left of the file's icon, letting you know it's a shortcut and not the real thing.
Making aliases can be a real help if your Dock is getting too wide to fit on your screen. It's also a great way to regularly edit a resume or note file, while still keeping all your documents in one location. Aliases don't have much to limit them, either, so you can even create one for a folder that's on another drive — a trick that's particularly useful for photos and video files.