I've been interested in a tablet for note taking as well. As an alternative I've also been thinking about a "digital pen". There's several out there now, such as this one:
http://www.epos-ps.com/products.asp?pid=1275&ppid=1278. Not an all purpose device, but much more portable and flexible for note taking. If I could just find someone who's used one of these
to get a meaningful opinion on them .