One of my favourite plugins for GEdit2 was tabswitch. It made GEdit more consistant with browsers by allowing it to switch tabs with CTRL+Tab instead of CTRL+PgUp/Down. Ubuntu 11.10 comes with Gedit 3 and the plugin no longer worked – so I rewrote it!
This plugin will let you use CTRL+Tab to switch between tabs in GEdit 3. You can download a working implementation here.
Install it by copying the files into ~/.local/share/gedit/plugins directory (which doesn’t exist by default) or /usr/lib/gedit/plugins if you want it to work for all users. Remember to enable the plugin in Edit – Preferences – Plugins for it to work!