Toggling between shadow states

Cross22

I was playing around with the "Dagger Dancer" tutorial and got frustrated that rendering it took 2 minutes even after sliding down all the renderer settings to minimum values.
I then toggled all light sources to not cast shadows, and switched the UE2 mode to ambient only. Preview time was now much better! For a final render of course I would have to remember to undo all these changes. This leads to my question: is there some kind of global state setting or maybe a script that allows me to switch between final light settings and "no shadow" settings ? What is the recommended workflow?