Disclosure: HP and Microsoft are currently clients of mine, and Toshiba and Apple have been clients in the past.
There is a growing belief that by the end of 2006 all laptops will have digitizers and the name, "Tablet Computer" may only apply to the slate designs. But we arent there yet and, currently, very few computers, notebooks or otherwise, have screens you can write on. Microsofts Windows XP for Tablet PC, and the tablet PC hardware were born in November 2002. The devices fall into two design categories, clamshell, and slate.
The slate design is basically a writable screen, with the guts of a notebook behind it, lacking a keyboard. The clam shell design is similar to a regular notebook but you can rotate the screen and lower it over the keyboard to create a slate like product.
Slate designs are popular with vertical markets and tend to be largely used for forms processing. Increasingly, they are also used in other applications, like design and architecture, where the ability to draw is valued. Clam Shell designs are vastly more popular but, in practice they are often just heavier notebooks – with the writing part used mostly for inserting signatures into email. The clam shell design doesnt force the user to abandon the keyboard-- so most dont.
Battle of the Slate Tablets: The Toshiba M200 is considered the best of the clamshell products. Its a strong improvement over their market leading 3500 which was released in late 2002. Its built around a 1.5 GHz Pentium M processor, with a 40GB hard drive and 512M of memory. The battery lasts between 3 and 4 hours.
The unique docking solution sets it apart from competitors. Much like Apples dock, its both practical and artistic. However, the dock alone costs nearly $400, which is a lot-- even if it is desktop art.
HP Enters the Fray: HP took a clean slate, no pun intended, in designing its new tablet. It is as if the HP designers sat back and thought "if there was a perfect tablet, what would it look like?" and went from there. It is a slate design that has a keyboard component that attaches to it (but could be left at the desk to save a pound).
The pound makes a huge difference if you are carrying it on your arm and taking notes with the stylus.
You can add 802.11 a/b/g wireless, which is important for a device designed to be used mostly away from the office. The HP is built around a slower 1 GHz Pentium M (or Celeron Mobile, basically a Pentium M without as much on chip cache), can be had with a 30GB drive. Alas, the battery life is less than steller – only about two to three hours.
It comes with its own desktop dock, which while not as flashy as the Toshiba, does the job. The dock can also remain attached to the laptop for mobile use. You can see how the two match up when docked in the picture below (note how the Toshiba Screen has glared out but the HP screen remains readable).