im using this one: http://www.recom-international.de/pdf/Innoline-2008/R-78xx-0.5.pdf
i used a linear type before, but at 20°C ambient the temperature inside my enclosure got up to 60°C, with the DC/DC style ones there is no raise in temperature.
have you checked your list for "dead" projects? for me only the MPGuino seems to be alive :-?