Edmunds.com has incorporated an interesting UI innovation with their breadcrumbing where the breadcrumbs also act as a sort of search filter.
This approach works particularly well in situations where you’re browsing product catalogs. In the case of Edmunds.com you can easily toggle between years, models, and makes. I could also see it having interesting implications on search results pages.
Beware applying this to breadcrumbs across the board. My team at Sequel tried this technique with a large corporate site and it didn’t quite translate. It ended up feeling superfluous.