Question about JKR site recent updates

[SongBird3411 at aol.com]

Hello all.  In the updates to JKR's site on the 10th, there were 
updates to the Rumors section.  I saw a lot of this stuff getting 
discussed over at the main list.  However, in my admitedly hasty scan 
of topics there, I saw little discussion about one point:  The method 
of communication the Order uses.  I only saw a few posts about this, 
and most of them were speculation on what the method would be.  One 
referenced some silvery material that came out of DD's wand in GOF.  
Though, no canon quote seemed to be provided with this. 

So, can someone tell me if there ever was any other discussion of 
this point at the main list since this issue was raised at JKR's 
site.  JKR was pretty specific in her answer.  The method needed only 
a wand and we have already seen it in use by an Order member.  I drew 
at blank at this and was hoping some list member with a better memory 
than me would have pinpointed it.  Did I miss it on the list?

I hate using Yahoomort to search for things.  I was hoping someone 
here might be able to answer.  I really didn't want to ask at the 
main list if this has already been discussed.

Thanks.

Mindy