In order for a stars position to change to due vantage point, you must travel very far. In fact, all the constellations would look the same if viewed from Mars.
Malaclypse is half right about us "seeing" the sun in different places. In order for us to understand this idea, we have to imagine the "celestial sphere", which is a useful tool for explaining this concept.
http://www.geocities.com/astrologyancientconcepts/images/equinoxes.gif
Take a soccer ball, for example. Imagine it spinning in mid-air. Now imagine yourself standing on the ball. At what to points would you do almost no spinning? The top and the bottom would be the right answers, or more specifically, the poles. The earth works the same way, except your vantage point is inside the "ball". For example, if you were living at the north pole, the north celestial pole would be directly overhead. With each movement farther south, or each step down on the latitudal scale, the north celestial pole would fall farther towards the northern horizon. If you were at 35 degrees north, for instance, the north celestial pole would be 35 degrees above the horizon. Now what happens when you go to 35 degrees south? Well, the south celestial pole would be 35 degrees above southern horizon and the northern celestial pole would be 35 degrees below the northern horizon. This is why some constellations are only visible in certain parts of the world. Now, the sun travels through 12 constellations each year, namely the zodiac. In November it is in Sagittarius, in December Scorpius, etc. For people in the northern hemisphere, the sun is pretty close to the southern horizon when it is in Scorpius, so it doesn't have time to heat the earth. However, because the southern hemisphere has that constellation higher up, Scorpius is overhead, allowing the sun to heat up the ground much longer.
I always (accidently) leave out info. when I explain things, so if any of this is unclear to you just ask. I'm not good at explaining things unless I'm constantly asked questions throughout doing so, so just ask away.
