DisplayLink&39's application turns an iPad into a secondary monitor for Windows.

DisplayLink announced an $1.99 application today that turns an iPad into a second monitor wirelessly connected to a Windows computer.

The application works with Windows XP, Vista, and 7 and requires an iPad with iOS 3.2 or later, the company said. It's configured with the DisplayLink software that the company offers for its primary line of business, USB-connected display technology.

"The productivity benefits of multiple displays has been proven, so leveraging the idle screen of the iPad while computing is ideal for parking and for running applications like instant messaging, e-mail, social networking, Web browsing, and other business tools to avoid constantly switching views on the laptop screen," DisplayLink said in a statement. That may sound like a lot of marketing fluff, but I love having a secondary monitor. Also, if you already have a DisplayLink-connected external monitor hooked in with USB, the iPad can become a third, the company added.

DisplayLink announced the technology today at the CES show in Las Vegas.

The software supports Windows 7's Aero mode, DisplayLink said, but it's not up to such as video games or high-speed video that need high data-transfer speeds.