Anyone with an aging iPhone, iPod Touch, or iPad knows that the device's once-instantaneous response to a home button tap can slow down over time. Luckily, there's an easy way to recalibrate the button and restore its factory performance.
Roberto Garza posted a Snapguide detailing the simple procedure, which doesn't take more than 15 seconds. It may sound like snake oil, but the comments on the page are almost universally positive, so it's certainly worth a try if your device suffers from this affliction.
Update: It looks like this is a myth that has been debunked. It's still a great way to force quit an unresponsive app, though, and is probably the cause of any temporary speedups you may see with your home button. If you're having problems with your iPhone's home button, try rebooting your phone or taking it in for service for a more permanent fix. Sorry for the misinformation!
Calibrate Your Home Button | Snapguide