I listened to Khyentse Rinpoche give a simple but very nice talk yesterday morning (simple usually is very for for Dhamma talks, I believe).
I talk was divided into three related parts; Avalokiteśvara, Om Mani Padme Hum, and Bodhicitta.
To sum it up, Avalokiteśvara's name is Perfect Perception. Perfect Perception is basically mindfulness; perceiving without attaching more to the experience.
Since mindfulness is so difficult to maintain, Om Mani Padme Hum helps bring us back to a mindful state, like a deep breath but more effective.
Finally, putting Bodhicitta (Enlightened Mind or Mind of Perfect Wisdom) into action, what ever we must do, if it's done with Bodhicitta, then it is the right thing to do, so do it.
This is perhaps overly simplified, but I recorded the talk on my phone and plan to divide it into sections go into more depth if I can manage the time. I'll at least get the recordings up for those who wish to listen, or I recommended looking up any of his talks online. Some of them are very entertaining, as well as insightful.