Sensory Bag- take a sturdy gal-sized freezer bag & dump in a large container of $ store colored hair gel. Toss a few small, non-pointy toys into the bag with the gel. Small balls/marbles work great. Big plastic buttons add nice high-contrast colors. Squeeze air out from bag & seal it. Duct tape to be sure. Tape the bag to smooth flooring for Tummy Time fun!
Would love to make an activity board like this fro the babies at work!