DH got a book before P was born with all sorts of activities for babies, and one of them was kitchen sand. Essentially its a sandpit in a dish. The book suggested using cornmeal, but that is really expensive so I thought I would be able to substitute wheat semolina, which is much cheaper.
It was such a nice day today that I took the sand outside and let P and J go wild with it. It kept them busy for minutes, and it also kept them from digging up the garden. The semolina worked really well, although it did get a bit gluggy when I tried to wash it out for J's hair (P quite happily admitted to pouring it onto her head in the first place).