Seti@home is unrealistic dreams, becouse alliens signals would be very weak if they living 1000 lightyears aways. It's probably unable to see 'siganl' of star at this distace, so how they hope to catch signal of aliens radio, etc?
Folding@home don't give at this time almost any useful benefit, becouse there nobody know how realy and why protein folds. And there is two opinions, that proteins folds into minimum energy state and thus solving NP-complete problems and another opinion that they don't solving NP-complete problem, becouse they don't reaching global minimum, but only local minimum. My opinion is that they don't solving NP-complete problems and that they solving much less than sciencist think - the same as quantum computers.
I agree that seti@home is nothing more then a dream at this point in time and might always. Due to the laws of physics, thermal noise, current technology and the limits of the 'isotropic sphere' of detection, we will likely never detect them by conventional radio technology.
That is why I only wasted a few years running that program before moving on to the health sciences. The World Community Grid seems to hold the most promise out of any distributed computing project I been involved in. They have a small basket full of health science projects running to develop better drugs.
If nothing else, it shows people can come together for a common good using relatively humble resources.
P.S - It's always a good thing to do a spell check