Ran into these people on an email list -- it seems to be a company that consolidates truck loads and can provide dramatically reduced shipping costs if you are willing to go from one carrier to another and wait a bit longer for delivery.
Check out Freightquote.com A number of people on this list are very happy with them.
Key thing is to arrange to have the delivery take place at a facility with a loading dock -- if the shipper has to send a truck with a lift-gate, this can cost $50-$100 more. Often you can persuade a nearby company to let you use theirs -- a six-pack works wonders...