One of my daughter's favourite songs at the moment is about elephants balancing on a string:
"Three gray elephants balancing
Step by step on a piece of string,
They thought it was such a wonderful stunt
That they called for another elephant.
Four gray elephants balancing...."
So, I taped a piece of sting onto the floor, and started teaching her how to walk on it, one foot in front of the other. I told her that we were walking on a piece of string over a creek and if we fell, we'd get all wet! She LOVED this idea. One moment Eden's carefully walking along our string, the next she's flinging herself off it, saying "I'm all wet now! I need new shoes Mummy!"; she would do anything for more shoes *sigh*.
This activity is suitable for all walking tots, just adapt your expectations to your child's skill level. It helps develop the large muscle groups in the legs, and hones their co-ordination skills. Tying it into the song helps them learn numbers, or reinforce numbers if your child already knows them. So simple!