Meditation is the process of slowing your thoughts down: a state of thoughtless awareness. It is not a religious or cultural practice. For years meditation has been touted as being good for you, but now Medicine is starting to prove its benefits: a significant reduction in blood pressure, greater powers of concentration and better immune functioning are found in people who regularly meditate.
Meditation can occur while sitting still with your eyes wide open. It doesn't have to be done cross legged in a lotus position (which I find uncomfortable for any extended period). The only pre-requisite is silence. Beyond that it's just about slowing your mind down. How you do that is up to you. It's the destination - not the route taken - that matters.