lift up the rear of the Macbook helps cooling?

I lift it up with a CD Case.

I did that too for the first couple of days.

But for me that was inconvenient, so instead I glued 4 bigger feet to the MacBook.

The feet raise it half a centimetre above the desk.

Both computer and desktop are now cooler.

I use a cardboard egg carton to raise my laptop. It works great.

It's simple physics heat rises so if you raise the back end of the mac you allow the hot air to rise away from the computer.

As for the 'share the hotness' idea, yes your MB and desk do share the heat but not equally unless you had a copper/aluminium desk and lots of thermal gel!

All you need to worry about is making sure the vents are clear for good airflow.

I've noticed that wooden desks seem to get hotter than metal surfaces -- wood seems to "hold" the heat more. My wood desk at home and the wood lapdesk I had would both get very hot with my MacBook, but when I used it at work on a metal filing cabinet or on a metal notebook stand, those didn't seem to get hot at all. The metal surfaces also appeared to keep the MacBook itself cooler.

As a result, I now use an iLap aluminum lapdesk instead of a wooden one. (It can also be used an a desk.) The aluminum stays completely cool, whereas the wood would get quite hot. I also put four round silicone pads on the bottom of the Macbook (they seem to be a bit thicker than the original "feet") that raise it up slightly for airflow and keep it from slipping on any surface.

Lifting up the back of Mac laptops always helps cooling. You can by stands that limit the amount of surface contact between the stand and the bottom of the Mac -- to improve airflow.

I too glued rubber feet on top of the plastic nubs that are there now. it even helps with the all-too-common hard drive vibration problem as well!