Ok, I think I found a way to do this. I was trying to get 2 photos to post side by side, with no luck.... so, I did it a different way. I am feeling so clever because it only too about 3 seconds to do this. I made a space for 2 photos on a single digital page in MDS, then added my completed layouts as photos on that page. I saved it to a file and cropped it in Picasa, and voila - it is now on my blog.
Thanks to the ladies that suggested editing 2 photos together - I am sure this isn't how you meant me to do it, but photoshop is too fancy for me! You probably think I did it the hard way, but it worked!
Just click on the photo to see the double layout enlarged.