Hello all, I just got my first mac tonight.....a macbook air. I must say, it is pretty amazing. But experimenting, i discovered that if you modify a photo, iPhoto makes a copy of it somewhere in its library (and on your hard drive). Does anyone know how to prevent iphoto from doing this? If i modify a photo, I just want it to overwrite the original (and not waste disk space). I have already un-checked the option to duplicate photos upon importing them into the library.....any help would be much appreciated. Thanks!