Barry, wouldn't it be a bit of a security thing that you can't run an OS off a USB stick?
Would it? Can't see the problem of running an OS off a USB stick, LiveCD or Installer, or a complete system on a stick. Either you have control of your server or you don't.
I'm sorry, but I just don't see what big security issue this is.
I just want to use a tool like 'unetbootin' and write the iso to the USB stick and boot from it so that I can install Astaro from a USB stick. Faster, easier and like my cute small jetway itx systems, some servers don't have a CD/DVD-ROM.
I'm also a fan of MultiBootUSB which Barry linked to. It's great to have a "universal" USB pen with lots of .iso files (even Win7 goes on there) and just choose which to start during boot.