Alternating between items from two layouts

I have created two layouts and I want items on the display to alternate from one layout to another eg:

Layout 1 Item 1
Layout 2 Item 1
Layout 1 Item 2
Layout 2 Item 2
and so on.

Take a look at Campaigns.

Campaigns allow you to assign Layouts into your choice of sequence. You would then only have to schedule the one campaign to your Displays.