I'm currently a Training officer in the Royal Air Force (UK) having served for 4 years so far. I did my degree in Physics with Space & Planetary Physics at Aberystwyth university in Wales, and have never lost interest in space exploration.
I know that as long as the human race is restricted to just this one planet we will always be vulnerable to extinction, so I wish that governments would take a long term view and invest in our future existence!
On a more down-to-earth note, I re-enact battles from the English Civil Wars (17th Century) when I find time at the weekends; I'm also studying for a second degree, in Philosophy.
Thoughts about SETI and SETI@home
I think that the chance of there NOT being any extraterrestrial life is so remote that it is not worth considering. If life can evolve on this planet then it almost certainly has evolved on other planets. Whether or not there is any other INTELLIGENT life (and I'm not going to try to define intelligence here!) is much more difficult question. I would think that there are so many potential life-bearing planets that it must have happened more than once in the universe - perhaps even in the Galaxy.
More important than this, though, is the search for habitable planets for humans to colonise. Our solar system will not exist forever, and although it will for a long, long, long time we should start considering our future now and not leave it in the hope that we will not be too late. It only takes one catastrophe to wipe out all human life whilst we restrict ourselves to one planet.