I searched and couldn't see that this had already been posted, apologies if this is old news. NASA has a number of sounds available to download as MP3s or M4Rs for iPhones. Have just downloaded some myself, including 'one small step for man' and 'Houston we have a problem'. These are the genuine recordings. They have an easy step-by-step guide to downloading and transferring to your phone, you just need your data cable to transfer between your computer and the phone.