LightBrush for iPhoto is a new 'local' image editing capabilities to iPhoto. Brushes available are Dodge, Burn, Underexpose, Overexpose, Desaturate, Saturate, Increase Contrast, Fade Contrast. There are controls for adjusting the brush size, brush softness and brush strength.
Of course the original files are not altered. Edited photos are automatically imported in iPhoto as copies of the original image. Give this great new iPhoto plugin a try by
downloading from Blue Crowbar Software (makers of the amazing and long awaited
Impression watermark plugin)
Above is an example of using the "overexpose" setting to lighten up the subjects faces from the original. Subtle, but effective.