Taiwanese smartphone developer High Tech Computer (HTC) debuted its biggest threat to the iPhone 3G yet earlier this week, the HTC Touch HD, and I had a chance to use one for a few hours on Friday.

The Touch HD more closely matches up to the iPhone 3G than other HTC smartphones because of its huge 3.8-inch screen, one of the biggest available on a smartphone, which has more responsive touch capabilities than the Touch Diamond or Touch Pro, which sport 2.8-inch screens. The iPhone 3G has a 3.5-inch screen.

I was impressed by the Touch HD.

The sleek 3G (third generation mobile telecommunications) smartphone is probably the best hope for a Microsoft Windows Mobile OS handset that I've seen so far in the battle against Apple. The Touch HD has a Qualcomm 7201A microprocessor, the same as the Touch Diamond, and Microsoft Windows Mobile 6.1 operating system.

The Touch HD's huge touchscreen is what makes it a better rival to the iPhone 3G than other HTC products.

The Touch HD's screen is speedier, more responsive, and far larger than the Touch Diamond, without losing the Diamond's striking display quality. The Touch HD's screen has WVGA (widescreen video graphics array) 800 x 480 pixel resolution. The screen on the iPhone 3G, by comparison, is VGA 480 x 320 resolution.

The only smartphone I've tried that compares to the HD touchscreen in terms of speed and performance is T-Mobile's G1 (the Google phone), which is also made by HTC.

For the record, I've not yet had a chance to play with the iPhone, which won't launch in Taiwan until December.

Ethan Chen, a supervisor at HTC, said there could be a few factors that make the HD's touchscreen seem faster than the Touch Diamond that I tried out back in June. First, the larger screen size helps because finger movements on the screen are more pronounced than on the 2.8-inch Touch Diamond. Second, the touchscreen software made by HTC, TouchFLO 3D, has been improved since the launch of the Touch Diamond. The Touch HD has the latest improvements, as well as tweaks specific to its hardware components, said Chen.

There is also an update for the Touch Diamond, which people can download from HTC's Web site.

The Touch HD performed well in a normal phone call with crisp voice quality and signal strength, and also created a sharp image in a video call with a Nokia N73. I had to wait several seconds for the video call to go through on Chunghwa Telecom's mobile network. The picture of me on the N73 screen was nice, but the picture quality of my friend on the Touch HD wasn't so pretty. I was told the difference in picture quality had more to do with the camera than the display.

The IDG News Service is a Network World affiliate.