Gruit Herbs

Does anyone have a list, or could we create one, of the herbs that can be used in beer as a substitute for the preservative qualities of hops? And how they are utilized to best access these properties.

So far I know Yarrow has all of the antimicrobial/antiseptic qualities of hops, and that you boil the leaves in much the same way, but I was hoping there would be others as well.

Some of the herbs I'm already planning on using in my upcoming experiments in Gruit: Licorice, Spruce tips, Ginger, Anise, and in at least one I will be using Yarrow

Best and first stop would be GruitAle.com for recipes and bits to get ready for GruitDay.com on 1 February.

Some great links would be this Herb and Recipe List:
http://beermumbo.com/gruit-ale/

Gruit history:
http://imbibemagazine.com/Gruits

WSJ Review on some fantastic gruits and their builds:
http://online.wsj.com/news/articles/SB10000872396390444897304578044733005355570

And why not a bit from the Mad Fermentationalist:

http://www.themadfermentationist.com/2011/02/tart-heather-gruit-recipe.html