With the K-2nd graders I did something related to weather. Coincidently, the weather this day was actually quite variable: one minute it was sunny, the next it was raining, foggy or cold, and then several rainbows popped up. Nice inspiration for the youngsters!
I had struggled with how exactly to rig the mobiles, with thoughts turning to wire coat hangers at first. But I turned to the old friend of the kinder-crafter...the paper plate;-) I initially thought of having the paper plate flat with the items hanging down from around the outside, but I was inspired by the rainbow to cut the plates in half and have the weather icons hang from the flat side.
This allowed me to have the rainbow take center stage and teach the kids the order of colors in a rainbow: Red at top, orange, yellow, green, blue (actually indigo) and then purple (officially violet). We discussed weather and the colors and that got the kids talking and thinking.
To speed things, I compiled a sheet of weather icons for the kids to color/decorate and then cut. I printed these on heavier card stock. They then had the choice or ribbon, yarn or pipe cleaners to hang these different items. Most chose a really blingy silver sparkle ribbon or pipe cleaners.
For this age group, this kind of color/cut/assemble project is amazingly effective, even if it is not incredibly creative. It is good for concentration and coordination.