I don't believe I'm going to get my Iapetus preview story in the shape I want it to be in time to post it today, but I thought you might enjoy seeing this image as a bit of a teaser. Cassini took the images for this photo from a distance of about 1.5 million kilometers, and it shows you how Iapetus is a barely-lit crescent. Cassini's forward view will continue to show Iapetus as a crescent throughout the approach phase of the September 10 flyby; it's only as the spacecraft passes the closest approach that it will swing to the daylit side of the moon.
Iapetus is one of the few targets in the Saturn system that actually has interesting color variations across its surface, so it is a lot of fun to create color images. If you want to give it a try as Cassini starts returning Iapetus images taken from closer and closer, check out my color imaging tutorials.