I have a lot of tags in my ignore list, and I mean a lot. It would be cool if I were able to simply click on a tag to ignore it, or maybe use a drag'n'drop action, moving the tag I want to ignore over the ignore list.
I use the ignore list for tags that I do not know anything about and tags that I know I am not going to answer questions for in the near future. Currently, I have to scroll a lot whenever I want to ignore a tag because my ignore list is so big. I do not want to subscribe to tags, because I like to "surf" the many new questions, and the ignore list helps me see only the questions that I know I can contribute to, either by comment or answer.