There is no substitute for sketching by hand, but there is also a need for forms of notation that help the UX grasp the functional scope at an early stage in the project. At the same time, for digital marketing sites it is important not to place undue constraints around the visual designer's contribution.
To address this I developed the idea of the Blueprint, a low-resolution form of wireframe in which the functional elements are allocated to their appropriate location without being too specific about what form they take or where they are in the page.
Link two or more blueprints together and you have a Functionality Map, in which different pages are represented and the links between them traced down to the level of the actual links in the page.
With suitable stencils and templates available the result is a tool in which websites and webapps can be rapidly mapped out and circulated for group discussion and development.
More recently a similar form of notation has been popularised by the Nielsen Norman Group under the name of "wireflows".