I looked up some tablet pcs from China. Tablet pcs are still developping. I need 2 full USB ports. When you use external 3G and a external keyboard at the same time you already need two such ports. A removable battery is good. Tablets mostly run surfing the internet not longer than 3 to 4 hours. You just have to stop working if a battery is empty. But you don't have to do so if you can just change them. But there is another point. If the installation of programs is in RAM, which makes working quicker as if it is on the hard disk, this will be deleted if you change the battery. There is then a need of a small battery (AAAfor instance) which keeps the installation during changing the main battery. This one must be easily accessible.