2000 Chrysler Concorde CAR WON'T START

Last summer (2009) I changed my starter and battery. It has worked flawlessly through the previous months. Just the other day April 10, 2010 I went to start my car and nothing happened. All the electrical components turned on and worked properly: windows, headlights, AC controls, heads up display, locks, etc. But when I went to crank the engine there was no sound. No cranking, no starter sound, nothing. I was thinking maybe the starter froze up or a wire came loose somewhere on the starter. The only reason I feel those two are possibilities are becuase the day before april 10, my car worked perfectly. Does anyone have some ideas? I don't hav any tools or jacks. Im in college and can't afford to have it towed. Please give me some suggestions.