Just dropping a line here to let you know there is a beta version of gradebookplus version 2 available in CVS contrib/gradebookplus_v2. I created a separate directory for those that may not want the additional capabilities of the newer version.
You can now directly add items to the gradebook. These items do not show up elsewhere in the course. You can also edit them like the assignment and quiz modtypes in gradebookplus.
Attached is a screenshot that shows two different moodle pages in one image. The top portion shows adding a graded event and the bottom portion shows editing grades for those who haven't checked out gradebookplus yet. Keep in mind that the demo course the shot was taken from only has 1 student.
Also, if you run into any problems post the issues here and I'll see what I can do to help.
This addon does create 2 new tables, but should be transparent to you. Since this does modify the database I would strongly suggest making a backup of your db before installing this addition.
Just to give credit where it's due: a large portion of the additions from gradebookplus to gradebookplus_v2 were originally coded by KJ who unfortunately is no longer working with us here at Humboldt. I mostly did bugfixing and adding in a few interface hooks as well as making the install cleaner.