Jell-O is one of those really great sensory accessories...smell, taste, texture, and it's changing state (liquid to a jiggly solid) make it perfect for sensory play and experimentation (we did Jell-O Volcanos last week).
This week, my kids were each in charge of preparing a different color Jell-O in a tub. They smelled each powder before adding water, and they tasted each liquid flavor before putting them in the fridge.
The kids each took a turn walking through the different Jell-O tubs and describing how it felt on their feet. The final tub was one filled with water to wash off their feet.
Once they all had a chance to walk through Jell-O tubs, I let them play in the tubs with their hands. They played with those Jell-O tubs for 25 minutes!