ofn-preset-guides

This plugin creates a "Presets" submenu in Image>Guides with sets of guides you use often, that can be if necessary invoked using hotkeys (see Edit>Keyboard shortcuts). Guide positions can be absolute or relative.

Example configuration:

Centered:centered:[.5]:[.5]
Margins @20px:margins20:20, -20 : 20,-20
Margins @50px:margins50:50,-50 :50,-70
Full Monty:fullmonty:[20,50,.5,-50,-20]:[20,50,.5,-50,-20]

Get ofn-preset-guides.zip from http://sourceforge.net/projects/gimp-tools/files/scripts/