The new PegII G4 processor has a cooler with fan as the most people know.
Did anyone try to replace it with a fanless cooling?

I doubt that anyone had time for that yet.. But IMHO it shoud be quite doable... I can't tell right away how big passive cooler you'll need, but it definitely needs to be considerable bigger (and hevier) than G3 version had.

I've not yet tried to make it fanless, but aimed more towards Dustless :)

In normal case the PSU Fan blows air out and at the same time the case takes the replacement air from the bottom holes etc. And at the same time it sucks dust & other particles inside the case.

Well there's 3 fans (cpu, voodoo, psu) in my case so one more couldn't hurt that much so i put on top of the case one fan blowing air inside thru a filter. No more dust inside, but noise got up a bit.

Gotta think of something to get the case noiseless & dustless someday :)