It depends on the environment as well.
Just for reference: (Penryn MBP Feb 08)
Currently the temperature in Singapore is 28 C, my CPU averages at 39 C and my GPU at 67 C with just some light surfing. This is 30 minutes after running 3DMark06.
In an air-conditioned room of 22 C, my CPU temperatures drop down to about 32 C and my GPU temperatures drop to 57 C.