Moving and magnifying (scaling)

Hey Guys,

Need some help with the next:
I have for example 9 pictures situated in a row. Now I want the pictures to move from the left to the right (or visa versa) with a constant speed and when they approach the middle of the stage I want them to slowly scale to say 150% and when they move away from the middle they have to scale back to 100%. So a gradient scale. Any help or tut. appreciated

THX