All of the cool kids are doing it now-a-days, biking!

I think I can cut down on my walking and my gas bill by getting a bicycle. Target has one on sale for under a $100. I just need two wheels, a frame and a comfortable seat.

So, here's my question, will cheaper bike affect my ride? What should I look for when buying a bicycle. I'm not going to ride the Tour de France so it doesn't have to be built from airplane grade aluminum. I just want something that will get me from point A to point B without a big wedgie and leaving me feel like I just peddled to the Point.

I'd appreciate your comments and suggestions!