I always think of it boiling down this way: In Geocaching, people place containers at places they find interesting in order to share the place with others. (some Geocachers really enjoy highway guardrails...etc. but we'll let that slide) In Waymarking, people make waymark pages to highlight things that are interesting in order to share the place with others. In Geocaching, the container is the find, in Waymarking, the place is the find.