Cable beat you in taking down their wires huh?It's called a utility pole, It used to be called a tree. I'm a lineman for Verizon actually removing a pole today. We throw old ones into a dumpster and then it's hauled away. I'm doubt you can buy them of if any foreman or management type would let you take one from the dumpster it's just the way they operate. here is a quick link from a Google search
If the length is an issue and you worry about them shifting/moving, you can drill them out at the ends and put in a nice, thick dowel or rebar to hold them together. I did this once with landscape timbers.Moving a telephone pole without a line truck is not fun. We had some pressure treated poles that were over 1200 lbs.
I like the 6x6 idea better. Still heavy but shorter and lighter.