Here's a little article called, "Meditation Techniques for Anywhere". The writer suggests the following:

Meditation as a personal stress-reduction technique can be practiced in solitude or in the midst of a crowd. Sitting at a desk at school or work, as well as on the meditation cushion at home can serve as a time-capsule of refreshment in the midst of 'busy-ness'. The silence within that is gained in moments of calm thought and even breathing carry over into ideas and events that follow meditation time.

Here are 4 meditation and centering techniques to privately use in public when feeling stressed:

1. Slowly count to 50. Just putting attention on this simple task calms. As my mind relaxes my body begins to relax; I feel better physically, mentally, emotionally.

2. Concentrate on breathing in an even pattern without holding the breath at any point. Counts 1, 2, inhale; counts 3, 4, exhale; continuing this pattern. I do this until I calm down.

3. While walking, take even strides and let arms swing in opposition to legs. This means that when stepping forward on the right foot the left arm swings forward. Besides calming this energizes me.

4. Sitting in a chair mentally relax each part of the body in progression beginning at the feet, moving up the legs to the trunk, arms, hands, chin, head, neck. Hold this physical relaxation for a few moments noticing tension drain away.

After one of the above stress-reduction meditations I feel more energy with the task at hand; the time-out is worth the minutes spent away from other tasks.

I always like tips for bringing meditation practice into all situations. A big part of making that work is simply wanting to.