When looking in our cabinet o’ stuff for something to occupy my two boys (ages 7 and 9), I came across a bag of mixed colored threads and a tutorial on the fine art of braiding commenced. While there are certainly more intricate DIY friendship bracelets out there (here and here for example), these braided ones can be made by most young kids without too much practice or frustration (caution: beware of tangled threads). In fact, once getting their fingers in motion, both boys had fun combining colors and filling up their wrists and ankles for a notable period of time. A couple were even created for mom and friends.
Tip: We used a clipboard, which held the project in place and made the activity portable. Thank you, designmom.com!