I wish there was a way to easily read case temperatures. A well cooled laptop can be hot as the center of the sun inside and still comfortable to use if the heat is vented properly.
The heat coming out of the fan discharge area on my work T60 ThinkPad feels like its coming from a hair dryer (so I know that the CPU and hard drive temps would read "HOT!"), but the casing never gets above room temperature.
To me, it's the comfort of the casing that matters.
This would be a pretty easy way to read case temps
http://www.maxtool.com/index/Digital_Infrared_Non-Contact_Thermometers.asp
And if you are bored you can carry the infrared thermometer with you and just check surface temps of stuff.