BogoMips is a freely available benchmark for CPU speed. BogoMips is also use in the Linux kernel to calibrate a timing function. The BogoMips mini-Howto contains a description of the history of the program and a compilation of results from a wide range of sources. There is also my own compilation of BogoMips results, which covers some extra platforms and shows results for operating systems on the same hardware.
The source for BogoMips 1.3 is available here as bogo-1.2.tar.gz. It is also available from the orginal site: http://sunsite.unc.edu/pub/Linux/system/status/
An updated version of BogoMIPS is available from http://submarine.dyndns.org/~djwong/programs/bogomips/. This updated version allows for the differences in the code used on different architectures in the Linux kernel.