I learned a little poem from a colleague of mine. The third graders love it. Longitude lines go up and down,, latitude lines go round and round. You can also draw two pictures. The longitude picture is a spider sitting on top of the north pole the spider has LONG legs,, then draw a ladder,, the latitude lines go round and round the rungs of the ladder go back and fourth,,This worked great, when it comes time for a test my students would draw the spider and ladder on their paper to help them remember. The poem is said in a little chant (animated) My students really get into it.