I believe the picture says it all (red grapes and watermelon on a stick). Leave in the freezer for at least 3-4 hours. Thanks to Janet for the idea.
Note for Young Ones:
As far as toddler safety goes, the grapes did not freeze solid during my experiment so they would be fine peeled and cut to the size your child prefers. The watermelon freezes very well and eats a lot like a popsicle at first. If your child is coordinated enough to hold on to the popsicle stick, it should work out well.