My iPhone 4's home button isn't working

Recently, my home button on my 4 isn't working. It was fine in the morning when I used it, but now for some reason it's become unresponsive. I have tried to recalibrate the home button by opening up the default calculator app, holding the power button until the "slide to power off" screen comes on and holding down the home button to force the app to close but that doesn't work. I'm suspecting this problem is from the countless drops my phone has suffered. Like just last week, I dropped my iPhone on the sidewalk and now my phone is chipped in the upper right corner (I didn't have my iPhone casing on then). But even after that it worked fine like usual until now. I'm thinking of restoring my phone and then resyncing it but I don't know if that will work. Is there any other way to fix the home button problem or should I bring it into an Apple store and have someone fix it?

For iOS 5 user, you can go to Settings > General > Accessibility. Under the section for Physical and Motor, turn on Assistive Touch. You will then see a small button pop up to the screen and seems to float around the screen. Hope it works out for ya.