The Dell Inspiron Duo is a Netbook computer with a flip over 10 inch screen, converting it to a touch screen tablet PC. Dell are taking orders for Christmas. No test units are avialable yet, so it is not clear how well the flip screen will work.
Reviews of the Lenovo IdeaPad S10-3t, which has a rotatable screen to turn it from a netbook to a tablet have not been favourable. While these units have the footprint of an Apple iPad, they are much thicker and heavier, due to them having a keyboard, hard disk and Atom processor (which in turn needs a bigger, heavier battery).
A better alternative for a convertible netbook/tablet might might be a unit with a thin membane (rubber) keyboard, which folds back 360 degrees, to the back the pad. The robber of the keyboard would be comfortable to hold.