Thanks all for all the info!
I also ordered the kit from dipmicro as suggested.
After "talking" to you I found this tutorial, that details what you have been explaining:
What bothers me is that it says: "Note that these techniques only work with the Arduino Duemilanove w/ an ATmega328, not the Arduino Uno (or older Arduino boards w/ an ATmega168)."
Now, the one I just ordered is precisely an Arduino Uno R3, but it has an ATmega328P.
I am puzzled, will it work?
Thanks
Luca