Andy2, sorry for such a cryptic question, but I wasn't sure if you were interested in switchers because of marketing hype or had a technical reason. I see you DO know something about the technical differences between the two types.
You are quite correct in saying linears are less noisy than switchers. However, you can still use a switcher in low noise analog circuits. The basic technique is to filter the switcher output, then use a low-dropout linear regulator to post-regulate the filtered output. The output of a linear regulator when used in this manner can be just as quiet as an all-linear power supply. The reason for the filter is most linear regulators are quite poor in rejecting the typically 100KHz to 1MHz switching noise on the switcher's output.
Digital applications still have analog output stages so they still need quiet supplies.
