quite an extensive disscussion going on over @ overclockers.com about heatpipes...
http://forum.oc-forums.com/vb/showth...hreadid=161052 for y'all register-ee's
To sum it up picture-wise:
And some others. Most are not avaible outside their respected contries, and in fact that blue thing I don't think really even is a heatpipe, but all the same, there they are.
Honestly, until the capiliary action (black) technical model starts being modified and copied, I'd watercool. The US military is contracting a major company to do advanced research on these heatpipes, but I don't think you'll see them on the shelf for more than a few years to come.
With the exception of the capiliary driven ones, heat pipes work primarialy through a liquid (usualy under pressure) boiling once it reaches a certin tempature, carrying the heat to another location to dissipate through either the air or a larger surface (the case with the deltatronics one), recondense, and start all over again. Even with a liquid with a very low boiling point (ie 40C), you would NEVER see tempatures lower than 40C. You'd unlikely see temps above that either, though, so it's really your choice. No pump noise, but I'd imigine your case would heat up pretty well after a while.
Also I'd like to mention seeing companies like Shuttle & Zalman manfacture heatpipes makes me shudder. They're compliciated devices; a few engineers at a small company don't have a chance of making an efficient one.