Shifting gears from the usual ranting at the Refuge, I came across a nice series of articles from Audio Design Line on the usage and selection of bypass capacitors in electronic circuits. This is a topic with which my students often seem to have difficulty. There is a nice tutorial on the modeling and behavior of capacitors and some practical info regarding the various types, with strong and weak points for each. One of my favorite bypass tricks is dealt with in some detail; namely placing different types and sizes of capacitors in a parallel arrangement to create a sort of "super cap" that exhibits superior performance when compared to any of the component caps.
Proper usage of capacitors in audio circuits almost seems to be a black art. This article should offer some insight.