Some programmers at XDA forum has done a good job of demonstrating Holographic Image on a HTC Touch Diamond. The program, VR Hologram is a simple proof of concept that the phone is capable of producing hologram images.
Video after the break
The program make use of the HTC Gsensor to track the tilt of the phone and change the hologram image accordingly. The phone must be flat in order for the tilt sensor (Gsensor) to identify its position properly.
Just a warning, from the forum, it seems that not all HTC Touch Software ROM can work. Nevertheless, for the adventurous, click here to reach XDA forum to download the software. Or you might want to watch the video first.