If you had to pick one of the most influential smartphones of the past year or so, there's little doubt the HTC EVO 4G would be high up on the list, if not atop it. It was the first 4.3-inch smartphone. The first 4G smartphone. And it it brought with it that sense of style that is a trademark for HTC.

Donn Koh was a designer with San Francisco-based One & Co. from November 2008 to May 2010. This was the design firm that gained notoriety with the Windows Mobile HTC Diamond and was later purchased by the Taiwanese manufacturer. Koh was the lead designer on the EVO 4G and has done a beautiful job breaking down the design of the device, which he says took a good 12 months from start to finish.

Koh tells of the team working directly with HTC's engineers, and of the challenges faced in combining large components while keeping it relatively (and deceptively) thin. In particular, Koh said, the EVO 4G's 8MP camera component, and how its design was incorporated into future HTC phones. Writes Koh:

While it was a requirement to highlight this key feature, it shouldn’t feel unnaturally big or loud. To create this balance, I needed to find an aesthetic solution that would somewhat mask the component size, and one that would look honest and purposefully ‘camera-like.’

This led to a spherical design that partially protrudes the outer surface of the phone. It created an interesting and iconic character akin to an eyeball sitting in a socket. I liked that it had the notion of the phone as a housing for powerful, intelligent, internal components.

This is a must-read if you're at all curious about what goes into smartphone design, and it should make you appreciate that little wonder in your hand that much more.

Thanks, David!

Update: The blog post referenced here has been made private; image and links removed by request.