USB Stick OS that can run .NET (or Silverlight)?

I'm doing an experimental project where I just need to be able to boot off a USB stick and run a .NET console app. The "boot" is important since the machine should be a dedicated appliance for time-sensitive operations.

Ideally this would be something like a Windows PE... but I don't believe it can run the .NET runtime... any suggestions on a way to accomplish this?

Mono is a certainly a possibilit开发者_StackOverflow中文版y, but just haven't used it outside of MonoTouch so have no idea how to accomplish, and if I were able to use the existing .NET code, that's a major bonus. Could probably use offline Silverlight as well.