Saw or read this idea somewhere of writing out various activities onto small pieces of papers and putting them in a small jar. When your child comes whining "Im Booored!", they pick out an activity from the jar. Maybe things like Create a Storybook, Draw a picture for a relative, Make Cookies, etc.
For a toddler version, I figure it would be more of an "Im Stressed" jar for me when my childs getting into everything she shouldn't because she's bored. Hers would have various activities like Make a Cave, Craft Ideas, Sink Play, etc.