Some astronomers say that in the grand scheme of things, 50 years isn't all that long, and the effort expended so far hasn't been all that exhaustive. "I think we have not yet begun to search," said Peter Backus, an astronomer at the SETI Institute in California's Silicon Valley.
But the technology is getting better all the time. "Fifty years ago, Frank Drake would never have imagined the directions in which SETI has moved," said Jill Tarter, director of the institute's Center for SETI Research (and the scientist who inspired the main character in the "Contact" book and movie).
Blogging this topic gives me the opportunity to finally get around to adding Alan Boyle's MSNBC Cosmic Log to the space section of my sidebar. Definitely worth checking frequently for wide ranging articles.