This Canvas String Art Graffiti project is fun for kids and adults alike. While this is a spray paint project, you can use alternative paints or dyes for younger children. Makes a fun summer art project when your kids get bored.
Log Bird Feeder - 23 DIY Birdfeeders That Will Fill Your Garden With Birds (my note: I haven't looked at all of these, but at least one is a terrible idea. The window birdfeeder -- birds could fly into the glass and hurt themselves.