I mentioned in the walkaround section that the display comes in at 3.8 inches, what I didn't mention is that the display also features VGA output at 480 x 800. The display also comes equipped with HTC Touch Flo 3D technology, if you've used an HTC Touch Diamond or any other HTC Touch Flo 3D technology based device not much has changed on the Touch HD, and I was okay with that, Touch Flo still worked as originally advertised, and thanks to the bigger and higher resolution screen the display was more crisp.
Aside from higher resolutions and Touch Flo 3D the unit also features excellent video playback, even the display video came in crisp with excellent sound. Videos play in the landscape mode and the play, rewind and fast forward buttons only display for a few seconds after which point the entire screen reality is taken up by the video, simply tap the display and the buttons reappear.
The display also moves in and out of landscape mode thanks to a competent accelerometer which changes displays quickly and works well with games on the big display.
One issue with the Touch HD I had was that the display is a resistive touchscreen which is great for using both your fingers and a stylus in unison, but it doesn't allow for the type of responsiveness found on the iPhone or iPhone 3G devices, it also lacks multi-touch. With that being said the large display and the ability to use more than one type of touch medium was definitely a plus.
Overall a great display that's perfect for website browsing, video playback, picture taking, and any other visual reason you can possibly think of.