I finally got a chance to sit down and browse the latest Scientific American issue a few nights ago. The Founder Mutations article (link is to a preview) was reminiscent of some of PZ's evolution posts, and was a good introduction to the idea of founder mutations (complete with some neat data).
The article that really grabbed me, however, was A Cool Early Earth? (link is to the full article), which discussed the discovery and analysis of some 4.4 billion year old rocks. The rocks weren't just any old rocks, they were tiny zircons about the size of a period; the article has a picture of more than 10 of the rocks contained underneath Roosevelt's nose (but above Roosevelt's mouth) on a US dime. The entire article is available online, so you can read it yourself, but suffice to say that these tiny specs are currently the oldest known rock specimens from the planet.
What interested me about the article was the technical precision required to carry out the research (the researchers took multiple samples from each tiny rock without destroying the rock), as well as the stress that the researchers must have been under while handling these ancient specimens. What if they sneezed?