My memory usage was soaring past 1.5 GB, so I closed the main culprit, a Firefox 3 RC2 with 20+ tabs opened. As usual, I thought it was time to restarts other programs as well.
This is not exactly new stuff, but I just recently found it.
Chimpanzees are known as a highly intelligent animal. They use stone and wooden tools, hunt in coordination, and can be taught limited sign language. What might be surprising is that on a particular intellectual test devised by Tetsuro Matsuzawa, young chimps outperforms university students.
Here’s a simple explanation of the test, which is actually a fun game: