For Cinco de Mayo in Kdg. - Plastic egg maracas - plastic easter eggs, fill them with what you want (candy, beans, etc.) 2 plastic spoons, wrap in colorful duct tape or plain masking tape and hand decorate.
Bottle Bank via Martha Stewart: transform a used plastic bottle into a cute piggy bank. Could use same idea to made little containers for kids to store their collections too (use bottle with wider opening and don't make slot)
Do you have old light bulbs that are not broken? Instead of just throwing them away, you can repurpose them as some creative things. Check out this list of Creative Light Bulb DIY Ideas and try one of them.