"Wearing red socks or shoes helps remind us to ground our bodies. Because red is a grounding color, seeing red on your feet throughout the day will serve as a reminder to bring your attention back to the physical body. This is especially helpful if you tend to ignore your lower extremities. By consciously focusing on the color red at your feet you will be energetically distributing your energies downwards, anchoring your energies to the earth, thus creating a better balance within yourself. Isn't it interesting that the Wicked Witch of the West in The Wizard of Oz story was wearing ruby red slippers? She got grounded when a house fell upon her while she was flying through the air. It was also the magical tapping of the red slippers together that brought Dorothy back home to Kansas."
The above passage, from About.com is interesting for a number of reasons. Firstly it highlights the link with the energies of the earth, which is a focus of the Outer Order, being centred in Malkuth. Indeed, the word for "red" in Hebrew is actually adom, which has the same spelling as adam, meaning "man", or, rather "of the earth". The "red" colour is related to the "ruddy" colour of earth, and thus the red slippers used in the Outer Order are a definitive link to earth energies, or, more aptly, those of Malkuth.
I'd like to highlight the part that says "if you tend to ignore your lower extremities", for this is, in a sense, part of the purpose of the Elemental Grades: to force you to explore these "lower extremities", that of the Lower, Elemental Self, and to ensue that you build the proper foundation upon which the life of the Higher Self will live.
The Wizard of Oz information is intriguing, and merely shows how such perennial symbols have permeated even our more modern expressions in book and film. The Wicked Witch relates to the West, which is the lowest portion of Malkuth, bordering the Qlippoth (and thus explaining her wickedness), but the West is also Malkuth as a whole, just as Tiphareth is the East, and thus she is tied intrinsically to Malkuth, even by the donning of the red slippers. The "magical tapping" of the slippers could potentially be likened to the Knocks used in ceremony, and further suggest the magickal depth that can be found in this film. It's hard not to think that there must have been some occult research that went into it. Regardlss, however, it offers us a modern mythology (just as the Matrix trilogy does for Gnosticism) that can potentially help us understand some of the more difficult aspects of our own tradition.