There are a million different options. I took a lot of stuff on the plane and UPSed a few big boxes. Check out Greyhound and Amtrak though. They both do discount shipping (takes a long time - but it's cheap). I think Amtrak can give you prices online, Greyhound requires a phone call.
You can also look into freight rates for pallets or check out the "hundredweight" options at UPS / FedEx, etc.
For cars - I think it's about $1000 to get a car all the way across on a train (no miles added). You could always hire someone to drive it - probably for free since they would be getting a free trip and paying for gas - try Craigslist for that. I'll ask my sister about car shipping - she shipped her car from Seattle to Boston.