Something that I've been thinking about lately is that maybe all of our sci-fi ideas on taking shortcuts to visit distant stars and galaxies is all just fiction. Maybe no matter how much effort and time we put in to developing new technologies, maybe we'll never be able to get anywhere much faster then we can right now.
Here's an interesting article on how long it would take to get to the closest star (Proxima Centauri), which happens to be 4.22 light years away.
One of the most optimistic theoretical methods, is nuclear pulse propulsion, which could possibly do it in 85 years. Granted, if you wanted to search for a planet that contains life, you would probably have to go much farther then that. Now, unless we figure out a way to freeze people for the duration of the trips, we would have to have a space ship so large that it's like it's own little planet. Some sort of self-sustaining craft that could recycle all the water and oxygen required to keep people alive. Depending on how fast we could realistically go, we would have to have generation after generation living on the craft.
If someone asked me if I wanted to go in to space, never see a planet again, only to raise a family so that future generations could make new discoveries, I would definitely say yes. As long as the spaceship was comfortable enough.
I know we're all kind of waiting until it's really necessary to do something like this, like if the planet is doomed or over-populated. We're also hoping that science can develop new technologies to do it in a faster way, but maybe we'll never come up with something that's any faster, and we should at least consider the idea of going with what we have right now. Is something was threatening human life, at least we could be somewhat ready if we started working on it. We can all see that we're filling up the planet quick, and we see our children as potential problems as over crowding is becoming a serious issue. Working on a project like this could shift that view, to one that's more optimistic.