Japanese scientists have developed a technique that can encode 100-bit messages into the DNA of common bacteria. The bacteria replicate and pass the message down from generation to generation for at least thousands of years. Because there are millions or more copies of the message it can survive gradual degradation or mutuations (so they claim). Perhaps by taking a sample of the message across a large number of descendant bacteriums any errors or mutations can be detected and corrected. The message that was encoded was ""e=mc2 1905".
What's interesting of course is that since this is possible it begs the question of whether there are already messages encoded into the DNA of various living things on Earth? We might want to look at E Coli, or other common organisms, or perhaps human, dolphin, and whale DNA. We might also want to look at birds and lizards since they come down more directly from dinosaurs. Who knows -- maybe a long long time ago someone left us messages there, or their signature at least.
There are two places that I think it is most likely that we will first receive messages from aliens, if we ever do:
- Our own DNA (or that of other living species on Earth)
- The Internet. It's the logical place to establish communication with us. Perhaps via a Myspace page...