This article focuses on mobile computing with a tablet PC, drawing from over five years of experience teaching with tablets in outdoor, field-based classes. In this article, the authors discuss three courses--Environmental Science, Ecology, and Biology--taught at three colleges. Each course is treated as a vignette from the point of view of a faculty member and a technology specialist. Though the courses are similar in that students use a tablet PC outdoors, the exercises and assignments, learning outcomes, faculty member's goals, and length of time using a tablet for class work all differ. In addition, student survey questions were not equivalent. The classes use standard off-the-shelf software or freeware, typically on Windows-based desktop machines. The pen-enabled tablet allows easy on-screen annotation and note-taking, and the software used has built-in digital inking capability. The authors' goal is to provide a wide-angle view of how to use tablet PCs as a mobile data-collection and note-taking tool suitable for students' use in the field. (Contains 7 figures, 2 tables, 10 endnotes and 3 resources.)