I recently started trying out GEdit over Kate and found that the plugins available to GEdit where quit nice. I really needed something that could do regular expression replacement which isn’t a part of the default Ubuntu package. After a few Google searches I found http://live.gnome.org/Gedit/Plugins which has a nice little package called regex_replace. The install instructions looked simple enough “extract the files to ~/.gnome2/gedit/plugins” but every time I did this the plugin would not show up in the plugins dialog.
The solution was trivial, I didn’t follow the instructions. When I extraced the tar.gz file it created a folder called regex_replace which I copied correctly, but it also created a .gedit-plugin file in the current directory! I was missing this file. Once it was copied the regex_replace.gedit-plugin file to ~/.gnome2/gedit/plugins all work as expected.