I've tried and now i'm shifting without clutch, it's fun and it makes you listen much more the engine sound, i'm trying to do it without the rpm's indicator and it's harder, but when you've done tree or four laps with the same care you get used to it.
I hope i can pass this knowledge into Real Life.
And by the way, is there any way of starting the car without the clutch? I mean when i'm stopped to put first gear and begin to run.