AirParrot Turns AppleTV Into A Secondary Display

From the FAQ on the AirParrot site:

What does AirParrot do?

AirParrot lets you AirPlay your Mac’s screen to a second or third generation AppleTV. What you see on your Mac’s screen will appear on the AppleTV, wirelessly!

How do I use AirParrot?

Once you’ve opened AirParrot, click on the icon in your menu bar. Select the AirPlay device (such as your AppleTV) and then select which screen you want to mirror. To stop mirroring, simply click on the same AirPlay device in the menu!

Displays: Go Long, Go Wide

If you want more monitors than you’ve got DVI or VGA ports, your options include adding a video card, using a USB-based display, or this Matrox hack: a small box plugs into your computer’s monitor port, and two or three monitors plug into the box, no software drivers or additional hardware required.

If you want to send a video signal further than your monitor’s cable, your options include getting a longer cable (works up to about 50′) or get a different cable. From MAKE and Doug Burbridge: a sending VGA over Cat-5. This device promises to send DGA up to 600 feet. Or, send DVI 160 feet.