Interesting thoughts at Tikkun's "What Is Shabbat, the Sabbath, Really About?"At this link you'll find commentary on Shabbat on the Politics of Meaning and Shabbat,
The Need for Ecological Awareness, The Need for Spiritual Awareness, Shabbat as a Spiritual Practice, The Basic Principles of Shabbat Practice, and Shabbat as a Message of Liberation.
"We are not stuck in a world of oppression. We are created in the image of God and hence embody this God energy in the universe. Our task is to recreate the world so that it conforms to the highest ethical and spiritual values. Lest we forget about this during our very busy and productive weeks, we are given Shabbat, a weekly reminder of our own experience of liberation from Egypt, and hence a reminder that we should not think of ourselves as trapped by reality or forced to define ourselves by what seems possible at the moment. Instead, we should reconnect with the transformative energy in the universe --God-- and be open to struggling to change the world."