This is a collage layout that I used b/c I had so many pictures from our vacation! I used black polka dot ribbon to separate the pictures.
Just a note if you decide to use this layout idea - I measured the pictures before I put the ribbon on and after I glued on the ribbon, I realized I had overlapped more than I anticipated (i.e. the pic on the bottom right, the poor chipmunk can't really be seen!).
Also, I used a clear/off-white stencil that I bought at WalMart for $1 or so to measure the first pic (I then cut the square out of the stencil) and then I placed it over the other pics to see if they would work at that size. I now have a template if I choose to do this layout again.