It was a traditional practice at the time of the Buddha for monks and nuns to practice the Development of Lovingkindness (metta bhavana)meditation as they walked around. They would do this while walking through town, begging food. They’d radiate well-wishing in every direction as they walked along the streets and through the marketplace.
Monks would also radiate Lovingkindness towards wild animals as they walked through the forests and jungles. India at that time was heavily forested, and attacks by snakes and other wild animals were common. It was considered that this practice was a good protection against snake attacks!
Even if you’re not at risk from cobras, you might still want to try practicing radiating lovingkindness as you do walking meditation. It can be a beautiful feeling to radiate love as you walk past people. You can start doing walking meditation in the usual way, deepening your awareness of your body, feelings, emotions, and objects of consciousness.
Then you can keep your focus on your emotions or on your heart-center, and wish everyone well. You can imagine that you have a sun in your heart, and that you are radiating warmth and light in every direction as you walk. Or you can repeat the phrase “May all beings be well, may all beings be happy, may all beings be free from suffering.”
This may also be an appropriate point to talk about what you do if you’re practicing walking meditation and you see someone you know. My suggestion is that you deal with the situation as you feel appropriate. If it’s possible, and appropriate, for you just to say “hi” and keep on going, then do that.
If it seems appropriate to stop and talk to the other person, then you can interrupt the walking meditation, but try to bring the qualities of awareness that you have developed in the practice into your conversation. You might want just to stop for a moment and say something like: “Hi there! I’d really like to stop and talk, but I’m practicing my walking meditation just now. Can I call you later?”
What you have to watch out for is on the one hand being rude through clinging to the idea that you are doing something so special that it can’t be interrupted, and on the other hand using an encounter with another person to avoid the practice. We call this “being precious” about your practice. Sometimes also we act out of guilt. We feel we”have to” stop and talk to this person because we feel guilty about spending time working on ourselves. This is something we should work hard to overcome.
If you do happen to stop and talk to someone, then resume your walking meditation practice afterwards, and at the beginning spend a few moments evaluating what your motives were in stopping. There is always something to learn from these encounters.
You can adapt the practice of walking metta bhavana to activities such as riding a bus or train, or driving a car. Rather than have your mind spacing out, you can direct thoughts of loving kindness toward your fellow passengers and to other drivers, pedestrians, etc. This kind of activity can powerfully enrich our emotional experience and leave us feeling much happier. Rather than idly daydream, and have nothing to show for it, we can find ourselves more at peace with the world and ourselves.