George Musser – an editor at Scientific American (and author of “The Complete Idiot’s Guide to String Theory”) – developed a diy version of the Wu-Shaknov Experiment. If George’s setup truly manages to measure the relative linear polarization of gamma rays from positron-electron annihilation, then he would have accomplished the most inexpensive demonstration of quantum entanglement!
The idea is to measure the relative linear polarization of gamma-ray photons emitted with opposite parity from the annihilation of positrons produced by the decay of Na-22 using Compton polarimetry and coincidence counting. The predicted results in the number of coincidences are different when assuming quantum entanglement than when basing the calculations on local hidden variables theories.