The Mill has released an iPhone application that can apply looks or emulate some basic color grading tools found in a grading suite. The app has some rudimentary preset looks, as well as controls for lift, gain, gamma and saturation.

Click here to open iTunes to the app in the store.

The Flickr group for images graded using the app can be found here.
FX Guide Article

Anyone who is involved with capturing or dealing with digital imagery in any way should read this excellent article by John Galt, the Senior Vice President of Advanced Digital Imaging at Panavision.