Actually, strike out the word "play" from above.
By watching my own kids, and now my grand-children, I've come to the conclusion that very young children are pre-programmed to EXPLORE the world via touch, taste, smell and hearing, while play and learning are just by-products.
Children, especially under 3 year olds, just soak up information like a dry sponge in a shower.
This post presents some of my ideas on creating a simple computer based "toy" to engage very young children, which will hopefully develop as they do.