Taiwanese computer manufacturer ASUS demonstrated their newest entry into both the burgeoning tablet and smartphone market earlier this evening at Computex.

Named the “PadFone”, this device is an Android powered smartphone that docks into a touchscreen tablet. This concept is not entirely new as Motorola’s Atrix 4G has somewhat similar features.

Both the tablet and the smartphone have front facing video cameras for video conferencing, and will share the same SIM card for access the 3G network. ASUS has not yet confirmed whether the tablet will have WI-FI support that can be used without the smartphone attached to it.

When the smartphone is inserted into the tablet the user is able to access all the functionality of the smartphone whilst using the tablet’s bigger screen and keyboard. Users are also able to switch seamlessly between the two devices: a video playing on the smartphone will resume right where it left off when the tablet mode is engaged; an in-progress email on the tablet will be exactly where the user left it on the smartphone.

In a promotional video presented at Computex, ASUS says that the tablet will not simply “up-scale” from the smartphone but display content at its native resolution. No word yet on whether it will support HD.

ASUS has yet to announce a number of key details such as which Android flavour they plan to use, pricing, or availability. However, it is widely expected that the PadFone will be out for the 2011 holiday season.