The original Project Ozma surveyed the nearby, Sun-like stars Tau Ceti and Epsilon Eridani at 1420 MHz for a total of 150 hours over four months. With an entire spectrum to chose from, 1420 MHz (in the L-band, if you speak that lingo) is at the spin-flip transition of hydrogen. Since hydrogen is everywhere, you can imagine that any civilization conducting astronomy would be paying attention to that frequency.
Last Tuesday, with the incredibly powerful Green Bank Telescope, Frank Drake re-observed Tau Ceti and Epsilon Eridani at 1420 MHz with Green Bank astronomers Jay Lockman and Karen O'Neil over the course of an hour. I hung back, watching along with other scientists and staff as a BBC film crew recorded the event. A bottle of champagne sat next to the observers' computer, just in case...
No extraterrestrials were discovered on that rainy afternoon, or else you would have heard about it by now. I did watch a man-made signal come and go on the spectrum analyzer, so strongly that it could be seen outside of the frequency range that the telescopes was observing. It was there no matter where the telescope pointed, which is often your first clue that it is a local signal. Good to know that there is still intelligent life somewhere!
SETI efforts roll on in a larger capacity with the Allen Telescope Array, jointly run by the SETI Institute, of which Frank Drake is an important part, and the Radio Astronomy Laboratory at Berkeley. Though we've been searching here and there in space (and frequency) for a signal, systematic searches have only probed so far into the galaxy. The ATA is needed to expand our search capabilities, and do radio astronomy along the way.