I have a Smart album in iPhoto that feeds images shot with my iPhone back onto my iPhone. So I'm never without those images. As this album grew by the hundreds it was getting more and more annoying to have to flick through the list to get to the most recent images. The iPhone has no control for ascending or descending order. However I found that iPhone will follow the sort order of the albums in iPhoto that you sync to your iPhone. So I changed the sort order of the Smart album in iPhoto to View/Sort Photos/Descending. Now the newer images are at the top of the album on my iPhone too.
