@Stefanino: I think Jessi was talking about tablet PC's (i.e. a tablet laptop) rather than a normal graphics tablet (where no-one will dispute that WACOM is the way to go).
I've been wanting to get my hands on a ModBook for ages, but they are only available in the US and Canada. If there is no pen lag (always an issue with tablets), then a Modook should be perfect.
@Jessi: Since you ARE in the US, why not see of you can try one?
More info HERE