First impressions
It's very small - but not quite as small as an Eee PC 701.
While the width is the same, the Eee PC 901 is both deeper and taller than the Eee PC 701. The difference in height is due to the larger 6 cell battery, and the increase in depth is likely due to the larger screen. Overall, its a nice looking small machine.
Let's take a tour around the Eee PC 901

Sorry about the dynamic range of the image - it is very tough to photograph something black on a white background.
On the lid we have a webcam, two microphones, and of course, the LCD.
The built-in web cam is a boon to those people who like to engage in video chat over the Internet - I fully expect that video telephony and chatting will become more prevalent as time goes by. 1.3M pixels is a pretty good resolution for a webcam.
The array microphone helps with noise cancellation and should make it possible to record audio in stereo.
Below the screen, we have the main body of the laptop. Let's first look at its top surface:
The largest amount of space is taken by the keyboard - unchanged from the Eee PC 701:

Above the keyboard we have four LED indicators, four special function keys and of course, the power button.
The four LED indicators are:
- Power
- Battery Charge
- Solid State Disk
- Wireless/Bluetooth

The four special function buttons above the keyboard are:
- backlight
- resolution
- speed
- skype

And here is the power button:

On the left hand side of the Eee PC 901 (and Eee PC 701) we have:
- Ethernet jack
- USB 2.0 jack
- microphone jack
- headphone jack
The Eee PC 901 has left out the optional place for a phone jack.

On the right hand side of the Eee PC 901 (and Eee PC 701) we have:
- SD slot
- two USB 2.0 jacks
- VGA 15 pin d-sub connector
- laptop lock connector

On the bottom of the Eee PC 901 we can see the cover of the ram/ssd bay, which is larger than the cover on the Eee PC 701.

Here is a closeup of how the battery area looks like:
