Telephone poles probably wont work. At their thin end, they are thicker than a caber at its thickest end, plus the outer surface of the wood is nasty with splinters and impregnated tar.

The best is just finding a tree, or calling a lumber company (lumber as in cutting down trees, not lumber as in Home Depot building dept.) and asking to have one cut. I think average price is about $10 a foot.