Sukkot is all about the interrelationship of the spiritual and the material. Originally, it was a celebration of the bounty of the fall harvest, and also a time of prayer for good rains so that the next planting season would be prosperous.
In the Sukkah, we look up at heaven through material that grows from the ground. When we look at the ground inside a Sukkah, we see the shadow cast by heaven. According to halacha (Jewish law), the things we use to perform the ritual of Sukkot, such as the lulav and etrog that we hold together and wave, must be owned by the individual using them. We plant ourselves in our sense of possession and ownership, and from there we explore what is "heavenly" about them or how we should use them or regard them.
The essence of the Sukkah -- the part that gives us the name "Sukkah" -- is the s'chach or covering. The walls are there only to hold up the s'chach! The s'chach represents the "Clouds of Presence" that hovered over the Israelites as they journeyed from Egypt toward the promised land. The Sukkah thus represents a way for us to perceive the infiniteness of the Shechinah or Divine Presence close enough to us, just over our heads, and in a defined area (if a Sukkah is so tall that you don't realize you're in it, then it doesn't fulfill the requirements). The Sukkah symbolizes the spirituality of things that are close at hand.
During Sukkot we say prayers about rain, and shake the "four species" (palm, citron, myrtle, and willow) that represent different paths of water in the plant world. (Click for more on Sukkot and water.)
In our times, we might use the experience of Sukkah and of lulav-and-etrog to think about the spiritual requirements of owning things or participating in an economy. It's a good time to think about the ethics of our consumption, about our use of water, and about how our upcoming votes affect how much bounty we have as a society and how it will be used and shared.