This article, which was posted to Automotive DesignLine on 11/7/08, describes how to use software-defined radio (SDR) techniques to receive a number of different standard signals, including:

• Digital Radio Mondiale (DRM)
• DRM+
• Digital Audio Broadcasting (DAB)
• DAB+
• Terrestrial Digital Multimedia Broadcasting (T-DMB) digital TV
• HD-radio AM
• HD-radio FM

It looks to me like these techniques could also be used in amateur radio. At the very least, the article is an interesting read.