I meditate while walking my dogs or taking a shower. Unless you are trying to achieve the title of Zen Grandmaster (which you probably are not) there is no need to sit still while doing so.
A Zen Grandmaster can probably meditate while rollerblading through NYC and simultaneously debugging a kernel driver. For beginners, it helps to sit relatively still with eyes closed (or eyes focused on eg a candle, tree, waterfall etc. but not darting about), to chant or use beads to count breaths, etc.