The boys love playdough. They used to play all the time but I think they started getting tired of doing the same stuff, so I was looking for some new ideas. I got this one and a few others from Teaching 2 and 3 Year Olds.
I set out a tray with playdough and a bunch of different kitchen tools (another thing both boys love to play with). This was a huge hit, to the point of them fighting over who got what. Love Bug of course pretended they were all different kinds of trucks building something.