Pervasive computing is a broad term that may have different meanings. In this talk, we will focus on its ubiquitous and persistent dimensions. Fundamental methods and conventional applications of pervasive computing are briefly reviewed considering the most common technologies (hardware and software) and user interfaces.Two innovative applications of pervasive computing are presented: Undercover2, a persistent world location based multi-player mobile game; and L-INK, a ubiquitous computing application based on photo-chemical principles.Undercover2 is an application that shows how to mix virtual and real worlds in a mobile environment. The design of its interface, game engine, messaging, positioning and billing system is described herein. Future developments of the game and related applications derived from the current market experience are also discussed.L-INK is an application where one attempts to escape traditional computation by either pre-programming or triggering a chain of photo-chemical reactions. One can then visualize the computing efforts in non-electronic surfaces such as textiles, wood and paper. L-INK is limited to pictorial calculus formulations. With this approach, images are not decoded numerically or verbally. It is shown that these formulations may be sufficient for a broad range of applications. They include interactive T-shirts, tables and paper maps.Innovation is invention translated into products that the consumer is willing to pay. The management of this translation for Undercover and L-INK, two pioneer applications of pervasive computing, is paradigmatic of the challenges facing a spin-off from university research. The log of the events that went from early brainstorms to products available in the market is presented for illustrative purposes.