Hi all, I have a question about Apple's warranty on my iPhone 3G 16gb. I have warranty until this September of 2009. My friend sold me this phone since he upgraded to a 3GS. It has also been replaced under warranty once. My question is can I still bring my phone in for a replacement since there is a lot of dust in my screen? Also, will I have to bring my friend with me while replacing my phone or will I just be fine going by myself. I have no receipts or anything with me too. Thank you for your time.