Sword of Gryffinddor - No No , not another horcrux theory :D

I do agree with xParanoiax that it could be about using it for magic but there could be another reason. You have to remember Gryffindor lived a thousand years ago. When things were very different and most humans and I'm sure wizard/witch alike had swords. It was just a part of life. So that is probably why he had it. Now whether it will be used in the seventh book who knows. I think with that book there will be a lot we aren't expecting.

Here it's possible we see yet more of her studies of real life pagans, witches, and wiccans. We use an athame which can be either a black handles knife or dagger..or a sword. It's I think one of the very few mentionings of swords with our practices. Alot of people use it because I think it's slightly more multi-use than the wand. A wand's pretty much only for directing energy -- or in the harry potter world for casting spells. In real life though, the athane is given the attribute of cutting things which may not normally be cut -- like spells, or non-physical entities.. I am not sure what Rowling will make the sword out to be, if she explains it much. But maybe this is a clue?