The role of the SETI institute is to research and educate about life in the universe, where it comes from, how it survives, and why, despite our spending the last 35 years transmitting the American Top 40 into the ether, nobody out there has got back to us.
The main work of the Institute revolves around developing new and better ways to search the universe for that elusive hint that we aren't alone. It supports research into how life formed here and how it might form elsewhere, in other environments. And in keeping with modern developments on Earth, it even has a Twitter account that you may use to post your message to aliens if and when we find any (http://twitter.com/SETiEarthSpeaks). It poses some challenging questions too: if we meet aliens, what do we say? How do we say it? What are they likely to understand? Will they be wearing digital watches?
The *******@home project, which many associate with the SETI Institute, is not actually an Institute project at all but one run out of the University of California at Berkeley. In brief, for the last ten years they've been encouraging home computer users to run some software in the background and when their machines are idle. That sofware searches radio telescope data, looking for signals from intelligent life.
Ironically, I used to run the *******@home software, back when it first started up and I had a comparatively slow machine (ahh... the good old days. A 386 cpu and an 80Mb hard drive and yes that's megabytes, not gigabytes, for all you young'uns out there). Now I have a machine faster than anyone's wildest dreams back then, but I haven't kept it up. Maybe because back then, there was a tantalizing possibility that someone was going to find the burst of narrow-band data that signaled the discovery of E. T, and it might well be ME. So the excitement was still there. Ten years on, the hope is the same but some of the glamor has gone out of it. Little men, green or otherwise, haven't sent us anything we can understand. Not yet. On the other hand, the populations of many local star systems have been receiving I Love Lucy for some time now, and they may be thinking exactly the same thing.