Attached are 2 files that I created in 2002-2003 about Location, Path & Attribute Breadcrumbs. This work on breadcrumbs was first presented as a poster at the 3rd Annual Information Architecture Summit, March 16-17, 2002.
Three Breadcrumbs Overview (280K, April 1, 2003 version) - 1-page example for each type of breadcrumb: Yahoo! for Location, Eddie Bauer for Path, Amazon for Attribute.
IA Summit Poster (550K, March 30, 2002 version) - A single PDF that includes the overview, the poster contents, and comments from attendees.