Gee, that new iPhone 4 sure is shiny, with its high-resolution, 326-dpi screen. But you know what? It's not the first to cross the 300-dpi threshold. That news comes from from an Android guru, actually. Tim Bray, who joined Google earlier this year and knows a thing or three about this business broke it down today on his blog. The Windows Mobile-powered Toshiba G900 and the Sony Ericsson Xperia X1 (remember them, folks?) both packed in the pixels back in their day. Of course, neither was a big hit in the United States, so we'll forgive you for not counting their pixels. Check out the whole hubub over dots per inch at Tim's blog. [TimBray.org]

Edit: Getting a high DPI is easy when you double the resolution but *don't* increase the size of the screen, which is what Apple did with the iPhone 4. Fact is, 3.5inch for the iPhone is on the small side these days for smartphones as HTC has made 3.2"  small, 3.6" the medium and 4.3" as large. 

Had Apple made a 4.3" screen to compete with the HD2, their DPI would drop to a less impressive 268

Incidently, the AT&T Pure is about 291 DPI, which while lower than the iPhone 4, is still in the ball park despite having a lower resolution. Why? It only has a small 3.2" screen. The Xperia X1 was over 300 DPI because it only had a 3 inch screen.

While a high DPI is nice, having a larger screen can be just as preferable, especially for reading on-the-go.

--Malatesta