Symbian has just put online some of the Workshops content that were presented at the Exposium'03.

Some of these documents are quite interesting:
  Advanced Symbian OS programming for the P800 - Introducing ECOM and ECAM will introduce the SonyEricsson Camera API (ECAM)
  Anatomy of C++ - Fast track to UIQ presents an overview of UIQ application and view architecture
  Multi-channel sound for games in UIQ presents the usage of the audio streaming API

More content is listed on Symbian site.