The Padfone was announced earlier today during the first day of the Computex exhibition in Taiwan.
The idea of the Padfone is that it will sell as a tablet/phone combo running Android. When one needs a bigger screen, say, for watching a movie or playing a game, you can just slide the phone into a slot in the back of the tablet, and your screen is suddenly magically bigger.
The tablet also has a bigger battery in it, so when your phone is low on juice, you can just pop it into the back of the tablet, and it will start charging.
With the Padfone, there is no need to buy a separate data plan for both the phone and tablet, because the tablet can just use the 3G data connection built into the docked phone.
Although it is unclear whether the tablet part of the Padfone will work without the phone docked inside or not, this seems like a pretty cool device. There are no details about pricing or availability, or even specs, which is definitely a setback. Another problem with Android tablets in general is the lack of tablet designed apps, at least with the Padfone, there is a smaller screen device to view phone-optimized apps.
Below are the two promotional videos that ASUS put out.