Yeah I never go anywhere without my Kingston Data Traveler. It has Windows 7 files in a folder, but whenever I want to boot the installer I only have to spill them out into the root as it's written to install.
Then there's XP, partitioning, cleanup/defrag tools, Rescue ISO, Works, several Offices, AV's, bootable HD diag and memtest, etc. etc.
Everything is backed up in my Downloads folder. I thought I had lost it so bought another one last month for $15 on Buy.com, but it turned up so that's now a backup, too.
The prices inch downwards, showing up a little cheaper every couple months on buy.com or Newegg. Get their emails to not miss out.