Toddler Stuff: Mess Free Play

This may seem silly but any game or toy that keeps a 2.5 year old busy and doesn't create a huge mess is a win in my life.  My girlfriend came up with this idea... give them a small jar with water and a big paint brush and tell them to "paint" on the chalkboard wall.  The worst mess that could possibly happen is they spill the water jar (which happens most times).