Smaller one... Simple PVC sprinkler that the kids can ride through on their bikes! My boys would love this and even the youngest on the trike could join in! Nice instructions here- click the thumbnail for step one :)

A tarp and sprinkler will create a fun splash pad for a slide. | 51 Budget Backyard DIYs That Are Borderline Genius

DIY Tutorial Backyard Waterpark- (Instructions and photos -

fun

Looks like a good Daddy project... all you need is PVC, a drill, and a hose.

Sidewalk Squirty chalk- SO FUN, and the chalk magically changes colors as kids play! {Only 3 ingredients}

PVC DIY - Bike Storage Is your garage cluttered with two-wheelers? This genius bike rack will introduce calm where there was chaos. For around $50, you can knock it together the same way you would any PVC DIY project—that is, by cutting and cementing. Though designed for five bikes, it holds twice as many if those bikes are child-sized.

Easy Change Artwork Frames. Holds 50 pieces of kids artwork. Only $8.95. Awesome!

Lots of cardboard box tutorials - so cool!

DIY Kids Jetpack

Kiddie Car Wash

Camping fun - knock ping pong balls off golf tees with water guns!!!!

Water Pillow I WANT ONE

many fun ideas

DIY Toddler Chairs {Made out of PVC Pipe}

My dad made us one of these when we were kids. I thought he was a genius because that was WAAAAY before Pinterest!! - homemade sprinklers

75 Things to do with your kids (many are FREE)..Traditions they will remember. One of the best lists I've seen.

Water Pinatas! Great for a hot day with the kids for fun

How to make your bath water glow and other totally awesome things to do with your kids. (This website is amazing!!) Ill be happy I pinned this someday!

10 Kid-Friendly Ideas for Backyard Fun: swing; play kitchen; water table; outdoor movies; sprinkler; lawn games; hammock