Will this work?

can i use a massive heatsink,with no fan, with a p4 2.4 prescott? i dont game with the computer im using it for, it is strictly for web, and burning dvds

How massive?

either a big scythe ninja, or an xp 90-120

i wouldnt. You can get a large fan that is near silent, but at least it will push some air over the heatsink. The problem with your idea is that the heat from the cpu has to go somewhere. If it goes to the heatsink it will radiate and warm the air in the case, and then heat everything up, and keep heating up. You need some air movement.

2.4 Prescott? Doesn't exist. You mean 2.8 Prescott? Or 2.4 Northwood (2.4C)? The 2.4Cs don't generate much heat and you should be able to get away with a TT Sonic Tower if you have some airflow in your case. The Prescotts generate quite a bit more heat and I'm not sure if that'd work, though it might. Of course, you can always get this:

http://www.zalman.co.kr/usa/product/view.asp?idx=151

Edit: The XP-90/120 won't work without a fan. The fins are too closely spaced and depend on airflow to dissipate heat. Some of the best-performing heatsinks with a fan could be some of the worst if you try to run them passively.

http://www.newegg.com/Product/Product.asp?Item=N82E16819116178

^ 2.4GHz Prescott

Get an XP120 & a Yate-Loon fan & then slow the fan down. You'll effectively have a silent cooling solution. Make sure you have good, efficient, airflow through the case.

I stand corrected. I always thought the slowest Prescott was the 505 (2.66) but I guess that's just for socket T. Anyway, you can always use a quiet fan with an XP-120 such as this one:

http://www.xoxide.com/cooler-master-120mm-fan-saf-s12-e1.html

I'm not sure how important it is to have a passively cooled CPU. If there are _any_ other fans in your system (northbridge, GPU, PSU, case, etc), you won't notice a near-silent fan on your CPU HS. If you plan to go completely fanless, though, you might need to consider that Zalman case. Even most of the passive CPU heatsinks are designed to take advantage of airflow through the case due to...you guessed it, fans.

I would say no, probably not. I'd also go with what the others suggested, get a heatsink and use a quiet fan. Something like a low speed panaflo maybe. Or if even that's too noisy, get a good quality 80mm heatsink that doesn't have the fins spaced too terribly tight and get something like this Papst fan.
19.4cfm @ 12 dBa. I would be VERY surprised if you were able to hear that (actually, I would be surprised if you could hear much of even a 20 dB fan, especially by the time it's inside your case).

I have bunch of 92mm Papsts (a bit faster) and actually you can hear them, but at lower RPM they're really great. Got them for around $4 each.

But when we talk about fanless CPU heatsink... Well, you could use Ninja fanlessly, but you'd need good case airflow, so it would be much better to use really quiet case fans along with quiet CPU fan (like Nexus, probably undervolted). If you got yourself Arctic Cooling Freezer 4 and decreased fan speed from 2200RPM to around 1500-1800, that should still perform properly, while being quieter than most of disks.