This paper presents IBrowser, a novel approach to enabling mobile users to perform their tasks seamlessly by collaboration between mobile devices and PCs in a pervasive computing environment. In the last few years, mobile devices such as PDAs and cellular phones have become small and powerful and provide network connectivity, because of this, a large number of people are using such devices. However, it is difficult for people to complete all tasks with a mobile device because of hardware limitations such as screen size and input methods. At the same time, it has become usual to use several low-end PCs in a network. Consequently, people use both mobile devices and PCs on a case-by-case basis to complete their tasks, often switching between them mid-task. Unfortunately, applications for mobile devices are not designed to collaborate with PCs, and so people have to manage the transfer of data and application states between mobile devices and PCs manually. This paper describes a system called IBrowser that allows mobile devices to communicate with PCs directly and lets users easily transfer data and browser application states between the two devices without having to do so manually. This paper also describes the design and prototype implementation of IBrowser.