You might like to check out the TabletPC, as I described here in an old entry to the PF blog:
physicsforums.com/blog/2006/05/20/tabletpcs-for-science-and-science-teaching/
(I currently use both a Dell laptop [for writing papers and doing computations while I travel] and an old Fujitsu slate-TabletPC [for taking notes, doing derivations, and lecturing]. I anticipate my next portable will be a convertible-TabletPC [hopefully with XP-TabletPC rather than Vista].)
Check out this subset of notebookreview.com:
http://www.tabletpcreview.com/,
as well as
http://www.gottabemobile.com/ [which isn't listed in the PF blog entry].
Many companies have an "accident protection" plan, which I took advantage of when I got my first Gateway/Motion slate.