One interesting note: At times, when I unplugged the sync cable, the iPad's video mirror image would disappear from the television, which would then search for an input signal and come up empty-handed. So while the 30-pin connector next to the HDMI out may be marketed as a handy port to keep your iPad charged while you glide through presentations on your TV, it seems a bit more essential. Regardless, this issue only occurred a couple times. Strangely, it seemed to have little to do with the iPad's remaining battery life, as it was nearly fully charged most times.

If you plan on holding the iPad 2 while playing a game or making presentations, you're going to want to be sitting or standing near a wall socket since the iPad's charging cable isn't terribly long. I would also recommend using the adapter with a long HDMI cable—the more slack you have, the easier it is to manipulate the iPad, which becomes less graceful when the Digital AV Adapter is attached to it.

The Digital AV Adapter outputs 1080p mirror images of your desktop, but when you play video, it defaults to 720p. When watching video stored on the iPad, you can tap a button in the screen's upper left-hand corner that switches between filling the screen entirely or using letterbox mode. If you're watching YouTube, the expand control on the lower left-hand portion of the video window switches between filling your television screen completely or playing the video within the YouTube app page, which appears in the image-mirroring, iPad-shaped window on your TV. When 720p video, say a movie purchased from the iTunes Store, plays via the adapter on a television screen, it looks very crisp. We're not talking Blu-ray level video, but it's nonetheless a high-resolution experience. Photos look similarly sharp, assuming they're not low resolution. When watching lower- resolution videos—say, some non-HD YouTube clip—the results are predictably ugly. Obviously that's not a knock on the adapter—low res footage never looks good when it's blown up, and there's not a whole lot you can do about it. That's why the toggle button for filling the screen or switching back to mirror-image size is so necessary.

The iPod touch (fourth gen), iPhone 4, and original iPad all play video and display photos via the adapter, but only the iPad 2 supports mirror imaging. In other words, if you were hoping to use the adapter to play games or view apps on your iPod touch on your television, you can't. iPad 2 apps, from games to, say, GarageBand, however, are mirrored perfectly, and in real time on an HDTV using the Digital AV Adapter.

It's worth noting that if you own an Apple TV ($99, 4 stars), you can use the AirPlay feature on your iOS device to stream video wirelessly to your television. In other words, for about $60 more, you can watch the same video you are sending via cable to your television, but wirelessly. However, AirPlay and Apple TV do not support mirror imaging, so the Digital Av Adapter remains a unique accessory--particularly if you own an iPad 2.

Sure, watching videos or photo slideshows, or gaming, from the iPad on your HDTV is a lot of fun, but the Adapter is useful too. Teachers can project lessons, and businesspeople presentations from their iPads. Is it worth $40? For iPad 2 owners, yes—it's a simple, all-in-one (well, minus the not-included HDMI cable) solution that helps you get the most out of your tablet and your HDTV. For latest-gen iPod touch, iPhone 4, and original iPad owners, it doesn't seem worth the price, as it can do far less.