Very loud annoying vibration motor iPhone 3G

Short Version: my warranty is long expired and still experiencing a problem the geniuses claimed was not a problem. My vibration motor is extremely loud in a very bad way, it sounds more like a rattle then a vibration.
Long version (please read) I got my phone 1 month after the 3G launch, and within a week experienced a 3G antenna failure. Took it in the my local Apple store and had another phone ordered for me. Received the new phone and no longer had the connection issues. I did however notice that anytime the phone would vibrate it would sound like something was lose inside the phone. I then took it in to Apple several times and they told me it was fine and I didnt have any issues. Being that this is my second iPhone 3G I knew they were wrong. Now im ready to throw this phone at the wall cause its very annoying to be in a quiet place and have everyone staring at you because everyone around you can hear you vibrating. My warranty IS expired but after some research online have found this is a very common problem and Apple should have fixed this issue for me the first time I reported it. Is there ANYTHING that I can do at this point to get it fixed or replaced.
On a side note I am kinda upset that I have never once dropped my phone on the ground and even if I did I have always had it in a protective case. I have some how developed several cracks surrounding my sim card slot and dock port.
Any help or information will be very appreciated. Perhaps a DIY guide to take apart the phone, Yes I know Apple does not condone this, if the geniuses will not help me.
iPhone 3G