I'd love to get my hands on a 2.5mm thick section of AMEC Thermalsol's innovative 'Flat Cool Pipe' given that it is rated for a Qmax of 270W! Stated thermal conductivity is between 5000-10,000 W/mK. The thermal cool pipes can be thought of as many small heatpipes formed side-by-side from hollow aluminum ribbon, instead of water as the working fluid, Acetone is used. Full technical details are here.
FULL STORY @ AMECTHERMASOL (http://www.amecthermasol.co.uk/AmecThermasolFlatCoolPipes.html)