One fun activity I tried last year was Salt Box Painting. Never fear, there's no paint involved. It's not even very messy. This is a great activity for kids four and under. Kids over four might enjoy it, too, but it might not hold their interest for very long.
To make Salt Box Painting, you will need:
-a shallow box or box top (a sturdy gift box top could work, too. Just try to find one that doesn't have seams or holes, so that salt won't leak out of it).
-colored construction paper (I chose rainbow colors)
-scissors (you might not need them if your paper is small and fits in the box without needing to be trimmed)
-tape (clear packing tape works best, but any tape will do)
-salt (regular table salt)
Cut the construction paper to fit the bottom of your box. You'll want to stagger it in layers. For example, if you want a rainbow effect, start with red on the far left side of the box. Then lay orange next to it, then yellow, and so on and so on till you reach purple. So you'll be continuously cutting the pieces so they fit in the box top in layers (unfortunately I don't have a picture of this step, but I think you'll figure it out). I taped the paper together and down to the sides of the box so it wouldn't slide around and so the salt wouldn't slide under the colored paper (the idea is to keep the salt on TOP of the paper). Clear packing tape works best for this.
Pour salt on top of your colored paper. The more salt, the better. If you don't use enough, you won't get the effect that you're really "painting." If your kids start to play with it and it doesn't look like they're "painting" in the salt, try adding more.
Then they can use their paintbrushes (yes, dry paintbrushes!) to "paint" letters, shapes and designs in the salt. The idea is that you see the colored paper underneath appear, so it looks like "paint" in the salt.
The Jersey Momma's boy is an outside the box thinker (no pun intended), so after about ten minutes of "painting," he wanted to drive his trucks in the salt and add Legos to the salt, and there were tire tracks and Legos and salt everywhere. Which is okay, I guess, but it left things messier than I had expected!
For a better tutorial and more photos of Salt Box Painting, check out Learning4Kids.