I'm pretty much at the same point as you, and I think I'm leaning towards a Samsung E251 (http://www.notebookcheck.net/Review-Samsung-E251-T4200-Esilo-Notebook.23893.0.html
) . The model NotebookCheck reviewed is still available, but there are also newer versions (Edoris) with slightly faster proc and Win7, and also one with discrete graphics (Elinah). These only seem to be available in Germany, which shouldn't be too much of a problem for you, but is somewhat of a problem for me, (finding someone who will ship to USA). One thing to be aware of is that the keyboard is German language and layout.
I8Kfangui is a great program for controlling a laptop fan, without it the noise from my current laptop would be intolerable. It was written by Christian Diefer (http://www.diefer.de/i8kfan/
), not Dell (in fact running it may void Dell's warrantee and is a little risky). Unfortunately I believe development on that program ceased some time ago and it is not compatible with newer Dells. There is a compatibility list on his website.
SpeedswitchXP was also written by Christian Diefer. It is quick and easy way to access the power mode settings of mobile CPU's. I think development on that also ended years ago, I don't know if it's even compatible with newer procs. It doesn't really matter though because there are other ways of accessing those settings. Just about any laptop you can get now will support power modes. It can certainly help but it's no guarantee of a quiet laptop.
Please keep us posted as to what you eventually get and how well it satisfies your criteria.