Here's a scenario that's all too familiar for a lot of us: You're on your way to an offsite meeting, and when you arrive at the building, you forget which conference room you're supposed to go to. You have the information with you, but it's stored in your calendaring program on your notebook. You have no choice but to boot your computer, load your calendar, get the info you need, and then shut everything down again.

No one likes to power up a computer just to check a quick factit wastes both time and battery power. To avoid this, many people simply write whatever important information they need on a sticky note and attach it to the outside of the notebook, but how low-tech can you get? Here's another scenario: You're waiting in an airport lounge and want to listen to music or catch up on some podcasts, but there's no AC outlet available.

How do you listen to the audio without draining your battery entirely? One solution is to configure Windows to not go into sleep mode when you shut the notebook lid. The computer remains running, but the screen turns off automatically when you close the lid, so you save quite a bit of power. However, to control the media playback, you have to open the lid anyway.

One of the most intriguing innovations in Windows Vista is a feature that lets you view information without starting up your computer or resorting to sticky notes, and lets you manipulate a program such as Windows Media Player without having to open the notebook lid. It's called Windows SideShow and it's a new technology that does two things:

• It enables a notebook manufacturer to add a small displaycalled a secondary display or an auxiliary displayto the outside of a notebook case.
• It enables Windows Vista to display information on the secondary display no matter what power state the notebook is in: on, off, or sleep.

If you use a clamshell-style cellphone, you've seen a similar idea: when the phone is closed, a screen on the outside of the phone shows you the current time, battery state, and other data. With Windows SideShow, however, you get a much more powerful interface that can display a wider variety of content:

• Developers of existing programs can choose to send data to the secondary display.
• Developers can build new gadgets designed for SideShow.

Microsoft created an application programming interface for SideShow, so third-party developers should create a lot of programs and gadgets that you can add to your SideShow menu.

Using the Windows SideShow Control Panel, you decide which programs or gadgets you want to appear in the SideShow secondary display. The list of possible gadgets was not finalized as I wrote this, but examples include a calendar (for example, Windows Calendar or the Outlook Calendar), email (such as Windows Mail or the Outlook Inbox), and Windows Media Player. Depending on the layout of the secondary display, you then choose which program or gadget you want to work with.