Move WordPress Comments
This plugin adds a small form to every comment on your blog. The form is only added for admins and allows you to move comments to a different page and to fix comment threading. This plugin is not designed for mass-moving of comments, rather for moving single comments from time to time. There are other plugins better suited for moving many comments at once.
The forms will be visible on every comment on your post/page, but not in the admin section. I found this more convenient than the existing solutions. There's also a widget included that allows you to turn the forms on and off in case you don't need them all the time.
Download it from it's WordPress.org page.
WordPress plugin demos are disabled as I don't use WordPress on this site any more.