It’s interesting to watch the trend of screen size and resolution in the UMPC and sub-notebook market. Every initial UMPC in 2006 that I can think of had a 7-inch display, which was the standard size defined the Origami Project. Over the next one to two years, designers learned that 800 x 480 wasn’t optimal so we’ve witnessed resolution bumps to a more useful 1024 x 600. The trend-setting Asus Eee PC started at the less than optimal screen size and res, but the next-gen model is already at 8.9-inches and the higher res. The HP Mini is an outlier with an even higher resolution on the 8.9-inch display.I don’t know what’s the “optimal” size and res for an ultra-portable device, and quite frankly, that varies for each individual. Still, I’m excited to see that some manufacturers are going just a wee bigger on the display: 10-inches. We’ve heard of Asus bringing a 10-inch Eee PC to market this year and it wouldn’t surprise me to see others follow; Dell and HP come to mind. 10-inches is a nice compromise between usability and portability. Perhaps not as much as an 8.9-inch screen, but certainly more than a lower-res 7-inch screen. I expect that by next year, 7-inch displays are relegated only to UMPCs while sub-notebooks gravitate towards the 8.9- and 10-inch sizes. Some LCD panel manufacturers are already shifting their production lines in this direction and one even expects to manufacture 1.5-million small displays this year. Not a lot when relatively compared to the mainstream 13- and 15-inch market, but quite a bit for a market that was practically unheard of two short years ago.Going back to the optimal size and resolution preference, I’m torn between 8.9- and 10-inches myself. I’d use either of these at WXGA and probably be happy and productive. How about you? What’s the ideal screen-size and resolution on your “dream device”?