Thanks for the links and repy 
Being that electronica (but not digital) newbie, I have decided to go out and buy the Velleman 8064 kit downtown. It cost me actually only ? 17,95. So I guess I saved out on frying 20$ worth of MOSFETs. (Not to mentioned converting schematic design into a real circuit).
It took me 2h 45 minutes to build it (I was very thorough and careful). I hooked it up to the 220V mains, lightbulb and Arduino board, with a small capacitator in parallel and TADA! An Arduino-controlled dimmer. : ))))
Next day I bough another 3 kits, and the next kit took me only 1h 20minutes to build...
So it's well worth getting one.
To all that read this post, here is another converted Massimo-believer (yes, he is always right) and a supporter of the Velleman K8064 kit.
Marcus