My interest in DNA pooling was always strong; we have developed methods doing this on the mass spec platform and applied it to the HLA region. I had, however, doubts if testing pools by less accurate methods like chip hybridization will work. The January issue of the AJHG now has a fascinating article how pooling may even work on the Affymetrix platform. Yea, yea.
DNA pooling can be even used in family context, see Wen Chung Lee in Cancer Epidemiology 2005 or Neil Risch in Genome Research 1998.