Showing custom taxonomy post count in sidebar

What I want is something like what AVH Extended Categories does, but with taxonomies. I currently have a widget set up in my sidebar showing a select few categories and their post count beside them in parenthesis. Is it possible to do the same with taxonomies? Say I have the taxonomy “location” registered and a term called “north america” in that taxonomy. I want “north america” listed in the sidebar showing how many posts are associated with it.

Also, I didn’t realize that when a taxonomy is deleted, the terms/categories/tags associated with that taxonomy remain. I don’t suppose there is any way of rooting those out in wordpress if you can no longer remember the names of the deleted taxonomies, is there?