Although digital libraries are intended to support education and knowledge work, current digital library interfaces are narrowly focused on retrieval. Furthermore, they are designed for desktop computers with keyboards, mice, and high-speed network connections. Desktop computers fail to support many key aspects of knowledge work, including active reading, free form ink annotation, fluid movement among document activities, and physical mobility. This paper proposes portable computers specialized for knowledge work, or digital library information appliances, as a new platform for accessing digital libraries. We present a number of ways that knowledge work can be augmented and transformed by the use of such appliances. These insights are based on our implementation of two research prototype systems: XLibris,™ an “active reading machine,” and TeleWeb, a mobile World Wide Web browser.