Note that having the current kernel header files installed in /usr/include/linux is critical to be able to compile source distribution of stand-alone modules --- i.e., for the Comtrol Rocketport, the PCMCIA drivers, the stand-alone serial driver, etc.
It is a really bad practice for certain debased distributions that they install header files for linux-2.0.0, but then install the kernel for 2.0.36. If you want standalone modules to be compilable in source form, please do *NOT* remove the requirement that /usr/include/linux and /usr/include/asm point to the current kernel sources on the hard disk. (Yes, this doesn't work if you're booting off an emergency boot diskette, but that argument is really a red herring. The header files should match the normal kernel which you boot, which is normally the default kernel installed on the hard drive.) - Ted