multiedit
The multiedit module allows an administrator to modify several nodes on a single page. It's useful if you want to change the taxonomy or workflow of more than one node at the same time. Known to work with taxonomy, categories (the Category module) and workflow. It might easily work with file attachments as well.
The code makes some tricky use of form_alter hooks. It uses those hooks in ways they were not designed to be used, which is why this code will remain in my sandbox instead of Drupal's contrib directory.
Here's the multiedit module source code.
Configuration must be done by editing a function near the top of the file. See multiedit_get_config(). The function returns an array which node types as keys, and as values as array containing the module names whos form_alter hooks should be invoked. As I said before, the form alter hooks are called in a way they were not originally designed for, so don't be surprised if not all modules work. But it works with taxonomy, category, and workflow, which are the ones I primarily wanted.
The other tricky part is coming up with the list of nodes to edit. Here is a way: Define a view (using views module) that shows teasers (or full nodes) of the nodes you want to edit. Also, enable the multiedit block. The block will provide a link 'edit the nodes on this page'. Now visit the view you defined. From there, click the multiedit link. I know this is a bit kludgy - another reason this code remains in my sandbox.
Another way to multiedit nodes is to write your own menu calllback. First come up with an array of nids you want to edit. Then use multiedit_build_form($nids).
