Emigrating from Earth?

The idea that humans might be able to live on other planets has interested scientists for a while now. With the increasing population growth on Earth, accompanied by a finite resource base, as well as the environmental problems surrounding climate change, the idea of moving to a new planet and starting over is appealing for a lot of people. But is this possible? Would another planet actually be able to sustain human life? Mars had been an area of interest for some time, because of evidence of water and its proximity to earth. The moon had also been a plausible option at one time... but both these ideas have been dismissed. Human life is very fragile, and we would not be able to withstand the extreme temperatures of either planet. On Mars, temperatures can go down to as low as -140°C, while on the moon, temperates can range from 130°C to -170°C! Humans must maintain a body temperature of around 37°C, and with a climate like this, this would be pretty much impossible.
Another major issue is transportation. How would everyone get to this other planet? It is one thing to take a few astronauts for a temporary visit to the moon, but for a mass exodus to occur, some kind of new technology would be needed. If we were to bring enough supplies to construct some kind of shelter, as well as provisions and other basic necessities, as well as the people who were going to be living there, the spacecraft would be much to heavy to actually go anywhere... So although the idea is really cool, the reality of living in space is probably not something that will be realised any time soon...
However, if you've always dreamt of living in space, don't give up hope yet! NASA's Kepler Satellite is orbiting the sun, scouring the universe for signs of other possible earth-like planets. There is a pretty good chance with all of the celestial bodies in our solar system, that there is at least one out there that is comparable to Earth... However, the transportation would still be an issue... so for the time being, I guess we better stick to Earth!