Did chimp and human ancestors interbreed? - LiveScience - MSNBC.com:

Based on the study of human and chimp genomes, the scientists believe the split between the human and chimpanzee lines occurred much more recently than previously thought — no more than 6.3 million years ago and perhaps as recently as 5.4 million years ago.

Human and chimpanzee ancestors began branching apart on the primate evolutionary tree about 9 million years ago, scientists say, but there are significant gaps in the fossil record. The new analysis suggests that a full split, which scientists call speciation, wasn't achieved for nearly 4 million years and might have occurred twice.

I think I know some folks who came from the second split.