Software tools that support or automate software engineering tasks are typically available on traditional desktop-based workstations. In contrast, mobile tools for requirements engineers offer considerable potential. In the last few years the capabilities of mobile devices such as personal digital assistants (PDAs) have advanced considerably. These devices now provide faster processing, increased storage, and improved connectivity. Hence, mobile computing will become a dominant computing paradigm. These developments let us envision mobile tools for RE that are sophisticated enough to be used in real-world projects.