The Oct. 9, 2006 edition of Time Magazine has a fascinating cover story about how humans evolved from other apes.
The chimpanzee genome was completed in 2005. When this was compared with the human genome, the variance was only 1.23%.
One significant difference between our two species is that chimpanzees don't appear to be susceptible to AIDS, Alzheimer's disease, or a particular type of malaria. Since our two genomes are so similar, a study of the differences may reveal a genetic basis for these diseases.
Check it out at What Makes Us Different?