I had the privilege of being in a lecture by
Paul Horowitz, and I was quite convinced it was worth the while to download an screensaver to make it process humongous amounts of data coming from space looking for some regular pattern. That was more than 10 years ago, and I,
along with some other people am wondering if it was really worth the while. It's really a longshot looking for aliens that way, by processing radio signals; but it's really worse to realize that, even if you keep looking for thousands of years and don't find anything, there'll be no guarantee that there are actually no aliens.
Recently,
Seth shostak has answered by pointing out that
Are we truly biologically or intellectually special? One radio whistle from the cosmos would answer that question
but, still, I would rather spend my idle cycles somewhere else. Funny thing is that the research results have been elsewhere:
BOINC, the volunteer-based grid computing middleware system, is now quite popular, and is being used for many different purposes. So I guess the baseline is that long-shot research is worth the while, even if results do not show up exactly where you were looking for.