I regularly do a one way sync of iPhoto from my desktop machine to my laptop. The instructions (translated for iTunes) are in
http://www.shirt-pocket.com/forums/s...ead.php?t=1688 but you should be able to figure out the equivalent steps for iPhoto without much difficulty.
One step I do now that isn't documented in the previous post is to close iPhoto on both machines and to dismount the iPhoto sparseimage on the laptop before running SuperDuper!.