There are plenty of Mac portable stands and cooling devices out there, but few can rival the moshi zephyr
for good looks. This cast aluminum stand incorporates a "high-thermal conduction interface compound" that contacts the bottom of the Mac and draws heat away to the heat sink and an "USB-powered ultra-silent fan (<20db)." The company claims around 10 degrees F of heat reduction on both the MacBook and Air.
The moshi zephyr seems to be designed for the MacBook and MacBook Air only and is available in silver or black for $75.