There are alternatives?
Get yourself a Mac Book Pro (15" is best for travelling and putting into hotel safes), Buy VM Ware Fusion and Windows XP (or Vista, I think).. and it gives you everything you need.
I used Parallels on 10.4 with not much free space, then switched to VMWare Fusion on 10.5 with lots of free space... so not a perfect experiment.. but VMWare Fusion on 10.5 works great!
And if you've not yet set up VMWare, just set up an account on logmein.com on your mac and windows machines, and you can access your windows machines using Firefox on your mac.
Most of my friends have Tablet PC's, but I never found a use for them. You can annotate PDF using full version of Acrobat, and a product called PDFpen (I have it but don't use it much)