The invention included to methods of forming CoSi.sub.2, methods of forming field effect transistors, and methods of forming conductive contacts. In one implementation, a method of forming CoSi.sub.2 includes forming a substantially amorphous layer comprising MSi.sub.x over a silicon-containing substrate, where "M" comprises at least some metal other than cobalt. A layer comprising cobalt is deposited over the substantially amorphous MSi.sub.x-comprising layer. The substrate is annealed effective to diffuse cobalt of the cobalt-comprising layer through the substantially amorphous MSi.sub.x-comprising layer and combine with silicon of the silicon-containing substrate to form CoSi.sub.2 beneath the substantially amorphous MSi.sub.x-comprising layer. Other aspects and implementations are contemplated.