BUILD AND DESIGN
There isn't much in the N900 that departs from the Nokia N810 it replaces. There's still a resistive touchscreen, running at a comfortable 800 by 480 pixels within 3.5 inches diagonally. At just under 270ppi, that's about as close to paper as LCD screens get these days.
Nokia N900However, the 3.5-inch screen does make it smaller than the N810; enough so that the N900 is a more comfortable pocket companion despite its additional heft (181g versus 221g for the N810). This additional weight is noticeable since the device is smaller, but usually the block (it's a rounded brick) doesn't weigh your pockets or hands down.
What the N900 does evolve rightly from the N810 is the QWERTY keyboard. The N900's is a three-row keyboard which ingeniously integrates directional keys on the right side. While it's smaller (width and height) than the one on N810, it feels much better due to its domed keys and excellent travel.
In using the N900 as my primary device, adapting to the QWERTY took only a few text messages or an e-mail.
Compared to my Nokia N97, the keyboard seems to have learned some lessons and offers easier blind typing, though the keys are closer together. The N900 lacks a directional pad, though, so you'll need to train both hands to use directional keys.
Like the N97's QWERTY, the N900 utilizes the function key to access numbers and additional symbols. However, those additional functions are not accessible by a long-press of the corresponding key.
Predictive text is enabled system-wide and many applications respect this functionality. That said, those coming from QWERTY devices like Treos and BlackBerries would be best to temper expectations. The N900 will learn the words you use very quickly, but features such as inserting a space after a period automatically aren't there.
Other Hardware Features
Once getting past the weight, shape, and large touchscreen, you see some of the design decisions that have evolved within this Nokia model. For example, the top of the device has a volume up/down, power on/off/lock, and camera capture buttons -- these follow the N810's design.
The 3.5mm headset jack has evolved to include TV-out (PAL/NTSC), yet remains on the right side. It's joined by a dedicated screen-lock toggle button and a well hidden stylus.
The bottom is bare -- on the N810 was the battery door release and memory card access. The N900 has the battery door as the entire rear panel. The micro-SDHC card slot is located under the this panel, as is the 1320 mAh battery.
The rear also houses one of the more significant upgrades for the N900: the 5 megapixel Carl Zeiss camera. This is a camera module similar to the one used in the Nokia N97 and other recent devices from this company. The camera is covered by a simple slider -- improved from the one on the N97 -- and has two LED flash blubs for better low-light pictures and video usability.
One of the neat features that the Internet Tablet line has always had is a kickstand. The N900 keeps this tradition going, but, unlike the N800 and N810 before it, this kickstand is actually designed around the camera-slider's chrome bezel, and doesn't do as good of a job in terms of keeping the device at a stable, angled viewing level.
Nokia N900 Review - Mobile Phones Club Blogspot
If there was anything in the hardware that I am most disappointed in, it’s the size of the battery (1320 mAh). This is much smaller than the 1500 mAh that ships with the N97 and N810, and the space is packed very tight. I don't know that third-party batteries would be able to fit without having some kind of new rear panel put on the device. This would make an already thick device much thicker.