Group offsetThis script basically does what Layer>Transform>Offset does, except it works on layer groups. All layers inside the group will be offset, including ones in nested groups - I used a recursive function so it doesn't matter how many levels of nesting there are.
http://registry.gimp.org/node/26996Should be useful for texture making.
Group change fontThis script changes the font and/or font size of all text layers within a layer group. Recursion optional.
http://registry.gimp.org/node/26997---------------All scripts install under "Group" top-level menu. I intend making more of these group tools in the future, which will all also install under "Group". If you don't like the creation of another top-level menu, feel free to modify the scripts for yourself.
Also taking requests - if there's anything you'd like to be able to do to a layer group, let me know and I can attempt to make it a reality (if it's not too difficult for me).
All scripts are released under GNU GPLv2.