Is Anyone(thing) Out There?

What's the most important thing that we as a now-global society could do? The updated equivalent of building the Library of Alexandria or patronizing the Renaissance?
To Lee Billings, author of the new book Five Billion Years of Solitude, the answer seems to be "discover that there's life on another planet." And despite the myriad of details he describes that complicate the search, it appears that we are just on the cusp of being able to make such a discovery.