I don’t recommend this because it’s bound to cause all sorts of warranty issues.
Sometimes your iPhone enters a mode where you can’t answer it unless you use your earbuds or bluetooth headset. Well, you CAN answer it, but you can’t hear anything. The handset speaker stops working. It appears that the iPhone still thinks the earbuds are plugged in so it turns off the speaker. This is how to fix this problem without having to go to the Apple store.
Here’s the video demo in ITunes/AppleTV/iPhone format
The headphone socket on the iPhone turns out to be a dust trap.So, apart from requiring you to have an adapter to use any other headphones, they also put a magic dust magnet in there. And if it collects on a contact in there, you can’t receive calls without a bluetooth headset or your proper headphones because the iPhone thinks the dust is the headphones.
Apple’s recommendation is to stick the headphones in and out 7-8 times so it acts like a brush. I’ve found that a little compressed air will do the trick as well (and no, I don’t recommend blowing into it as your breath is warm, moist air).