Topper had a great way of making sets that you could use to build bigger and more crafty things. If you look at the mold (click on it for a larger pic) you will notice that all the tiles have posts to make holes in the corners. In the top left center of the mold picture you will also see the yellow connectors that have posts with flared ends.  I bought this set for my daughter, she thinks its so cool that you can design your own purse. I have to find a way to make more of those connectors.