Mobile and pervasive computing has seen a rapid development in the last years. Portable, handheld computing devices are getting more popular as their capabilities increase. Therefore, people having the need to work on-the-field have now the possibility to be supported by computer technology, for example, garden or building designers. Ad-hoc networking capabilities of handheld devices enable the development of supporting tools for collaborative work anywhere. This paper presents MCSketcher, a system that enables face-to-face collaborative design based on sketches using handheld devices equipped for spontaneous wireless peer-to-peer networking. It is especially targeted for supporting preliminary, in-the-field work, allowing designers to exchange ideas through sketches on empty sheets or over a recently taken photograph of the object being worked on, in a brainstorming-like working style. Pen-based designed human-computer interaction is the key to supporting collaborative work. The gestures-based command input results in a lightweight yet efficient and easy to use interface. Graph structured hierarchical documents help to overcome the problems of a small screen size. (C) 2007 Elsevier Ltd. All rights reserved.