OS X has pretty good app/window management. You can do fancy stuff like have it layout all open windows across the screen, have all windows moved to the edges for a view of the desktop, minimize windows with a keystroke, and open new and restore minimized apps if your using quicksilver.
However, After 6 years of working in the virtual desktop paradigm it’s something I’ve been missing on my Mac. Fortunately there are two solutions currently available that add virtual desktop functionality to OS X, Desktop Manager and Space.app
Space.app is functional. It adds a pager that sits on the desktop as an app and allows you to setup shortcut keys to switch between desktops.
Desktop Manager, however, is what you want. It brings cool visual desktop switch transitions, key bindings, a desktop pager, a pager that sits in the File, Edit bar (Linux like), mouse to screen edge desktop changing, and options to control mouse locations after a switch.
Slide, cube, reveal, and swap over are my favorites.
Also, looks like this is going to be a future feature in OS X