With PowerPoint 2010 and Windows 7, it is now possible to show a PowerPoint slideshow on a projector and view your notes on your laptop. Yes, Macs/Keynote have been able to do this for a while, but finally it is an option for the PC as well. The big advantage of this is that you can see your notes on your laptop while the audience sees only the slides in presentation mode.
After the projector is attached to your laptop, go to
Start > control panel > display > connect to a projector > extend.
The next step is to make the projector the primary screen and your laptop the secondary: click on display settings, click on the projector display (likely #2) and then check “make this my main display.”
When you run PowerPoint, be sure that it is showing on the laptop before you start the presentation. When you start the show, the presentation slides show on the projector, but your editing view with notes will be on your laptop.
Leave this setting alone, and your laptop will use it whenever you are connected to a projector.
One disadvantage: if you have other applications that you’d like to show the audience during your presentation, you’ll have to be able to navigate them while looking at the projected image (your laptop will be blank…)
More info on effective use of PowerPoint here.