My time as an internet nomad, with no (functioning) computer to call my own, has been made much more bearable by a de facto collaboration between friends- like
littlebreeze, who has let me use her computer as if my own- and the good folks over at
PortableApps.com, who basically produce a computer-on-a-stick.
I can basically walk up to any Windows PC and have my own e-mail apps; documents; browser with bookmarks, last-open-tabs, and history; and Nethack.
All without interfering with the PC's installation in any way.
It's a big thing.