I've created my own contributed utility called SandboxieReflector. SandboxieReflector allows you to define commands that force designated applications to always run in a certain sandbox, also when called from inside another one. This can be useful in several ways; e.g.
when you want to force certain apps to run in their own sandbox, thus not polluting other sandboxes along the way (run FireFox in it's own sandbox even when started from another sandbox), or
when you want to install apps in their own sandbox, and be able to run them from anywhere (also from inside other sandboxes).
