I'd LOVE to see a module that cleaned up things like:
Users with no group permissions
(non-custom) Blocks with no module link
Modules with no directory (deleted from web server)
Modules without the required tables

Basically a system to clean up the orphaned blocks and modules on our databases. Somehow over time I've managed to aquire a butt-load of blocks listed on the group permissions page that don't even exist. I also have blocks that have no modules linked to them any longer and a whole host of other little issues like that.

It'd also be nice if this module would allow the admin to drop tables that are no longer being used by any modules. I've removed some modules in the past and noticed that it leaves the tables intact.

Last night I tried emptying the modules, blocks, new blocks and block-module link tables then re-installing all of the modules (commented out the sql's in the xoops_version.php files). That didn't work so I restored my backup of garbage filled data.

This sounds like a great idea -- a general maintenance and tune-up module.

I ran across a Backup block not long ago that backs up your site's database and stores on the website or emails to you. It would be nice to merge that functionality too.

o yes, that would be terrific. unfortunately my php skills are rather limited, so i couldn't do it myself.
the backup module btw is here. works great but obviously doesn't give you the options phpmyadmin does.

Here! Here! That's a great idea.