I Dream of Greenies

Do you ever dream about money? I had a dream last night in which I was taking money out of my wallet to pay for a hotel room, I think. I can't remember the rest of the dream, other than a part when I was riding on the top of a double decker bus as it went along an elevated highway that was almost like a roller coaster. At one point, it seemed to be descending in a huge spiral that was so steep I thought I was going to fall out of the bus and into the water below. I often have really vivid dreams, full of weird adventures and crises. I think all my anxieties about life emerge in my dreams-- I'm trying to avenge some wrong that was done to me, or I'm back in college and I have to register for courses, but I've forgotten the book that lists the ones I have to take, so I have to go back to my dorm room to get it, but I forget where my dorm is, and then it's too late to get to the class I want to take, and then I realize I have no clothes on, etc...
I think I've had dreams of that nature where I needed to buy something but didn't have any money, and then went into some chain of events involving trying to find my money and then losing track of whatever I was supposed to buy... but otherwise, I can't remember many dream situations where money came into play at all. Perhaps I think about this stuff so much in real life it has no need to invade my sub-conscious dream life?
Do money matters invade your dreams? What do you think it means when they do?