Safe High Yield Transaction

So where do we put our "safe money"? I use to think Muni's were a good idea because of the unique tax features but with all the turmoil in economy I now question their stability. The ability to service mounting debt with increased municipal service demand at the local level is making me nervous. Bank CD's seem questionable because of the limits on the safety net and relatively low returns. In searching for alternatives, I have recently been looking at traditional stogy instruments that have tax features, stable issuers, and comparatively high yields. Some of these seem to combine all the components to make them a good choice for stability, safety and strong comparative performance. I am continuing my pursuit of finding a good place for my safe money but I think I have found one or two that yield 6.4% before tax for a five year commitment with a number of other interesting features.