What form factor?

The Nokia N810 Internet tablet has a sliding, backlit keyboard and an 800 by 480 display with 16-bit color and a 105 mm diagonal screen that can be read in sunlight. It has 2 gigabytes of flash storage and 128 megabytes of memory. It has a 640 by 480 camera for still photos and video and WiFi, Bluetooth, MiMAX (optional) and USB connectivity. The table weighs 226 grams and measures 72 by 128 by 14 millimeters. It uses Nokia's operating system and mapping service, and costs around $400.
The Eee PC 901 compact laptop is one of many models available from Asus. It has 1 gigabyte of memory, 12 gigabytes of solid state storage, an 8.9 inch screen with 1,024 x 600 pixels and a 1.3 megapixel camera. It measures 8.9 x 6.9 x 1.5 inches and weighs 38 ounces, and connects to the world through 3 USB ports, Ethernet, and Wifi. There is also a VGA connection if you have an external monitor. The 901 comes with Linux, StarOffice 8 (which can read and write Microsoft Office files), firefox and many other programs. The battery is claimed to last for 6 hours, and Asus throws in 20 GB of online storage (easily accessible via a desktop icon), which enables you to download up to 5 GB of data per day. Would this machine satisfy all of your computing needs? This machine sells for around $450 today. Similar models with Windows cost a bit more. But, what will it cost in a few years? Will Asus offer these "nettops" with Google's Android operating system? Will your ISP give you one for free if you sign a two-year contract? Will Google subsidize the sale?
This Microsoft Research prototype is like a personal "black box" recorder, logging your activity for a day. It is a badge-sized camera (inset) that takes up to 2,000 fisheye VGA images per day. It is automatically triggered by changes in acceleration, lighting or temperature, and is programmed to recognize when a new person walks into a room or when there is a person nearby. A hand gesture by the user manually takes a picture. All the technology we take for granted -- word processing, LANs, the PC, laser printers, etc. -- begins with research prototypes like this. This work is done in both corporate and university labs.
The final comment on mobile and portable form factors, has to do with pocket-sized miniature projectors, which we discussed here. These may one day be built into portable and mobile Internet access devices. David Pogue has written a mostly positive review (the video is great and the audio bad) of an early miniature projector.