I've just purchased this monitor (Philips 240PW9ES).
I can confirm it is silent enough. And you can trust me, I am quite sensitive to noise.
It is not completely silent, though, except maybe at 100% brightness (which seems to be the case with many, if not all, LCD monitors?). When I lower down brightness, I can hear a very small buzz/whining (if I try hard enough and if I am close enough to the monitor), then when approaching 60% brightness the level of sound will start getting lower and lower and so on. I use this monitor at around 50% brightness anyway and I can not really hear it. My ambient noise is: my computer (fairly silent) and lamps that emitt some buzz/whining - do not know why - maybe we do not have a very "clean" 220V "signal" - maybe this is the reason this monitor emitts a little sound after all?
Before this one, I purchased some Samsung monitor (2443BW) and it was pretty loud - it emitted a very audible buzz/whining (expect when at 100% brightness). I returned it to the store.
I still have Philips 19 inch 190P, which is completely silent.
I use it for dual screen now.
I hope this helps anyone.
As far as silence of Philips 240PWES is concerned, I am satisfied. But there is one other thing I personally find not so good: my previous monitor was 19 inch, and this is 24 inch and 1920x1200 and it has smaller dot pitch, which means that things (especially fonts) are a bit smaller. I had known that before I purchased it, but did not think it will bother me. I changed DPI in Windows Vista from default 96 to 106, now text for me is OK. Note that when in Ubuntu Linux, fonts are big enough for me at default 96 DPI. Interesting. This is my personal preference that I like text to be large and legible - those of you who are used to reading text on laptops with high resolution would probably not find that a problem at all.
So, now I am thinking of buying a 26 inch monitor (and selling this one) with the same resolution (1920x1200) that obviously has a higher dot pitch (pixel size) and should not require changing DPI. The problem is there are not so many 26 inch monitors on the market yet and that they are fairly expensive - at least if one wants quality.
EDIT: spelling and terminology