I definitely believe that there is extraterrestrial life somewhere in the Universe. Take into account the amount of exo-solar planets. There are likely hundreds within our own arm of the Milky Way. Accepting that intelligent life elsewhere in the Universe, as vast and incomprehensible as it is, would be highly elitist and narrow minded.
Most people will reject the notion of aliens because it is not in their "norm". Confining oneself to a small narrow-band train of thought that life is just what happens in your day-to-day living is what is making the notion Extraterrestrial life so extravagant and such an aspect of science-fiction. Whereas, in the broader spectrum of things, life beyond Earth isn't that much of an far-fetched idea.
Of course travel is a huge issue, but then again, if you think beyond what is usually canon, then the possibilities seem to become more and more. It's been theorized that thermal energy from nuclear power could propel a craft far into, and past, the heliopause. Electromagnetism could be another answer, it would be a powerful source of clean, and efficient energy.