Many of the diverse pleasures that people experience during recreational computing activities can be synthesised into a single concept known as flow. Flow is a state of intense mental focus that occurs when a person’s perceptual and cognitive systems are challenged at near capacity without being exceeded. It typically results in feelings of enjoyment and reduced awareness of factors that are irrelevant to the task at hand. For example, sometimes while surfing the Web or playing computer games, people become so immersed in what they are doing that they lose track of time and temporarily forget about their physical surroundings, their sense of self and their usual concerns. Flow experiences are not limited to computing activities. People report experiencing flow while working, participating in sport, performing music, engaging in hobbies, and doing many other things. This paper suggests some instructional design principles that could potentially make online learning more conducive to flow experiences, and hence more enjoyable and intrinsically motivating. These suggestions have arisen from the findings of a qualitative study of the flow experiences of Web users and computer game players.