DIY -- Backyard Race Car Track, this site has different ideas for making your own Racetrack in the yard.
17 Fabulous DIY Pallet Projects For Kids
15 Simple Science Projects For Kids @ in-the-cornerin-the-corner. Have done these before. They are awesome and the kids love them.
diy outdoor water walls for kids | Kids Music Wall via ‘Coupons’
Water play A great water activity board - maybe someone's talented parent or grandparent could make one for your centre?