Such a great idea! Keepsake box for each trip you take! Via This, That and the Other Thang I love this idea for making a keepsake box full of mementos and pictures from a trip, rather than trying to scrapbook everything
How to keep a child busy for hours in the summer: DIY: Giant Ice Cube Awesomeness - filled with plastic animals, dinos, and such. And I'm sure you could put in food dye before its frozen to color it like the ice block in the photo.
this one sounds even easier to make: bubble snakes = easy quick craft. Cut the bottom off water bottle. Put old sock over bottom and duct tape. Add food coloring for fun. Dip end in dish soap mixed with a little water