>> "Its still a bit perplexing that nothing of this sort has already been written elsewhere. "

i think that are two main reasons because not generic solutions are available.

1. Has no good way to do this *GENERIC*! Breadcrumbs reflect specific aspects about your application and in few cases is more than just split controller / action in li items. Many questions should impact on what i want with my breadcrumbs... I want show where the guy is, or how he come here? I want items as links or not? and if want links, for where should they point to?... I always want just the name of the action (with gsub('_', ' ')) or i want customized titles for my itens? This is just a small set of questions. The biggest point here is: this is not very very application specific feature?

2. for simple solutions as you presented, less than 20 lines of pure ruby code is needed! You really think that has reasons for a plugin???