Okay, well we aren't there…yet.
A long time ago, when we got our first Apple laptop, it was only possible to set up a dual display system on a PowerBook. The poor iBook wasn't able to support the feature, it only had the ability to mirror displays.
Fast forward a few years, and now all your Apple laptops can support a dual display setup. That's how we work at home, because it increases productivity by a boatload. It allows us to use one screen for browsing through the news and sifting through PR emails while the other screen is used for typing.
That said, you may want to try it for yourself on your home setup.
Let's go over some of the basic setup instructions for getting your extended desktop display running with your laptop:
1) You will need Apple's Mini DisplayPort adapter: Here. Please, make sure you get the connector that's right for your external monitor (VGA or DVI). Just look at the pictures below and figure out which fits the connector on your monitor.
2) You will then have to connect the monitor to your Mac via the Mini DisplayPort.
3) When connected, you will go to the Apple menu at the top and open up your System Preferences.
4) From your System Preferences, go to Displays.
5) When you click Detect Displays, the computer will see the second display. From here, you can adjust the resolution of both displays. Unfortunately, Apple laptops aren't quite at a 16:9 aspect ratio (as are most external displays). This means they won't exactly match.
6) If your displays are mirrored you will have to click on the Arrangement tab. The arrangement window will show you a small graphic representation of your displays.
You can uncheck Mirror Displays if you don't want your computer to simply provide two of the exact same image on two screens.
You can click and drag the screens into any arrangement you want. You can literally arrange them just about any way you'd like. You can stack them vertically, arrange them horizontally, and we even tried diagonal just for kicks. It works.
From that same menu shown above, you can also move the menu bar by dragging it to the screen you'd like it to sit in.
7) You don't want to skip this step. Under your Displays menu, you can click on the Color tab. The window should have the name of the connected display. Hit Calibrate. This will take a while, but it's very necessary. The application will guide you through the steps to help you match the colors and brightness of your displays. If you skip this step, chances are your second screen will be a real eyesore to look at, because it will be darker/lighter/bluer or anything but matching your other screen.
Additional Application You May Be Interested in:
There is an OS X desktop application called SecondBar. It's cool because it gives you a second menubar if you have a dual display setup. Unfortunately, it's still in the very early stages of development and the developer warns that it does have its bugs.
Feel free to check it out, and download at your own risk. We tested it and it hasn't given us any problems, but everybody's system is different. (Note: it only works with Snow Leopard) Link.