For our Long & Short study we used pgs 104- 111 in the Comprehensive Curriculum of Basic Skills for Preschool.
First, we simply arranged pieces of paper from shortest to longest. If you want to make it a little more interesting you could use rainbow colors or slice up a picture from a magazine that will be revealed once placed in the right order.
For our next game, I put some painters tape around a tile and had J try to push the cars into the square. Depending on where it ended up, we'd say "too short" and "too far." We didn't use the word long but it was a good exercise in distance, length and fine motor skills.