I'm a bit nervous about switching from PC to Mac. One major thing I'm worried about is my photo library. I have thousands of pictures. If I switch to Mac and import these into iPhoto, where will these files "live"? I've read that they will exist in one huge iPhoto database file. Is this correct? If I make a change to a photo through iPhoto (red-eye, etc), is this just a change to the database or is it a change to the file? Does the file even exist anymore?