Enter the tablet/netbook hybrid. A number of different companies make such devices and I have personally owned ones made by Dell and Asus. Asus actually makes two such devices, you can see them compared here.
Today I would like to compare two 10" netbook/tablet convertables: the Dell Inspiron Duo and the Asus T101MT.
Size and Weight:
The Dell Duo is slightly larger and heavier than the Asus model with dimensions of:
11.22" x 7.66" x 1.03" and weighing 3.39 pounds.
The T101MT comes in at:
10.39" x 7.13" x 1.22" and only 2.86 pounds.
Both netbooks have chiclet keyboards so typing on both is a pleasant experience. Because the Duo is physically larger though it's keyboard is just a bit bigger. Because of this it has an over all better layout. Even after a full year of usage I still miss hitting the right shift key on the T101MT every now and then because of the keyboard layout.
Keep this in mind though. I personally use the touch screen largely for taking written notes. A resistive screen is much better suited for this purpose. 40$ and three capacitive stylus's later I have yet to find one that is as accurate/as good as using generic resistive stylus for such a task.
External ports is the one area where hands down the T101MT crushes the Duo. The Duo only has three ports: 2 USB and an audio out. The T101MT on the other hand has pretty much what you would expect from a netbook. 3 USB, audio out, microphone in, SD card reader and VGA.
Thats right - they couldn't even squeeze an HDMI mini onto the Duo.
This may seem like an odd thing to mention, but the T101MT does have a much better AC adapter. The Duo power brick comes with a short cord by default and does not have a light on the brick letting you know it is on. The T101MT also comes with Velcro ties by default for packing up the adapter neatly.
By default both laptops make the choice of coming with a platter hard drive. The Duo comes with a 320gig 7200rpm drive. The higher end T101MT comes with a 320gig 5400rpm drive and the lower end model comes with a 250gig.
As someone who firmly believes hard drives with moving parts are a piss poor idea in both tablets and netbook I have replaced the drives in both units. In this respect, both units are poorly designed. With the T101MT you need to tear apart almost the entire unit to get to the drive. The Duo requires, not quite as much, but still a good deal of work to get at it's drive. If you are not someone that works on mobile hardware on a regular basis I would not recommend doing this upgrade yourself.
Both these units come with copies of Windows 7 by default. You are not stuck with this OS though. Linux works equally well on both the Duo and the T101MT.
The Dell Duo is right around 600$ (depending on where you purchase it from) and the higher end T101MT is close to this, right around 550$. If you are looking to pay a bit less than this the lower end T101MT comes in 100$ less around 450$.
I'm not going to say here which unit is better. As with many things the answer to this question is "it depends". It depends on what you are looking for, it depends on what you need and it depends on what you are looking to spend. Hopefully my summary here will help you choose which of these two units is right for you though!