I've seen that method mentioned in a few places and it seems to work for some people but not others.
My PS3 got the YLOD about 2 months ago and I didn't really fancy sending it to Sony and getting a refurb replacement for £130 so I tried the re-flow method of fixing it. I followed the video posted above (there are a few variations depending on what model PS3 you have) and afterwards my PS3 was up and running again.
It lasted about 2 months before it crashed from over heating again, although after leaving it a couple of days it worked fine on it's own but I don't think it will last long. I think the important thing to know is that whatever you do to try and fix it will only act as a temporary solution and you will have the same problem again in a few months (which varies in each individual case).
