Here's some beautiful info about the Sanskrit character OM that I found on my last trip to the book store. Breaking down OM shows you the journey this mantra leads you on - into the subtle, spiritual realms. Enjoy!
"Find your conscious mind - Look at the top curve of the "3" shape. This is "aaa", signifying your conscious, waking mind.
Drop to your subconscious - View the lower loop of the "3" shape. This is the sound "uuu", which denotes and taps into your subconscious, a far greater space than the waking mind.
Discover your unconscious - Find the separate curved line flowing out from the junction of the main "3" shape - this is the sound "mmm" and relates to your unconscious. Then find the little half-moon above the main sympbol - this is maya, the veil of illusion that masks the deep truth of transcendental awareness turiya, which is represented by the dot, or bindu."
"The mantra OM is the universe. It is Brahman (the absolute). It is time - past, present and future. It is also that which transcends time."
Mandukya Upanishad (800-400BCE), India