Copying and pasting adjustments in iPhoto!
The "Adjust" feature of iPhoto is the most advanced editing that can be done in iPhoto. It has been greatly improved in iPhoto '08. There are many new possibilities hidden in there. One of the things that was overlooked in every presentation of the new iPhoto is the Copy/Paste. This is actually very useful. You can tweak the settings and if you want to compare with the original, you can simple press "Copy", then "Reset", check out the original and press "Paste" again to come back to the modified version. It can also be useful if you want to apply exactly the same settings to pictures that have the same problem. You can easily copy it and paste it in the settings of another picture.