Need for Smart Breadcrumbs (or more Breadcrumb options)

If you have a store that really requires customers to use filtering and sorting such as ours (unworn vintage shoes), the current Breadcrumb code is problematic.

We have a couple thousand pairs of vintage shoes, but few of the styles (some 800+ or so) have more than 1 or 2 sizes. So customers need to filter to find their size (length + width) on the category theme page, then search through the results. If they click an SKU to view it on the product theme page then use the Breadcrumb to return to the category page, all filtering and sorting is lost. This leads to frustrated customers which leads to them leaving the site (arg!).

To be a 'true' Breadcrumb, it should retrace the actual path a customer has taken — including previous page activity. The current Breadcrumb doesn't when any filter or sorting is applied. In short, there should be a choice of Breadcrumb trails with one that returns customers to the 'previous' page(s) much like a browser's back arrow would.