A convertable netbook may be what you a re looking for. Asus is apparently about to introduce two of them, there is also the Gigabyte Touchnote T1028M
and Intel's Classmate PC "tablet"
. Note that these are running Windows XP Home, not Windows XP Tablet PC Edition. Vista has more support for tablet stuff (i.e. it is already a "tablet edition), but requires a more powerful computer. Battery life is always something to watch out for.