I'm sure many of you iPhone users have found that your home button may become unresponsive or has a noticeable delay when you click it. Here is a neat tutorial which might fix that problem. I say might because it doesn't work for everyone but has worked for many.
How To Fix Home Button on iPhone
1. Open up a stock app on your iPhone. Like the Weather or YouTube app.
2. With one of these apps open, hold down the power button at the top of your iPhone until the "slide to power off" screen comes up.
3. Then quickly press the home button repeatedly until the phone goes back to your homescreen.
That should be it. Remember it won't work for everyone. It didn't work on my iPhone 4S but it did seem to work on older iPhones like the 3GS and original 4th generation.
Another thing you can simply do is restart your iPhone or upgrade its software. Simple things like this also fix the problem. It fixed my iPad 2 when I upgraded from iOS 4.3.3 to iOS 5.
Let me know if you have had success or not.