That being said, I have been hard at work on a post concerning the Rebel Yell. I posted here about finding a video clip, from the Smithsonian, of a bunch of old soldiers giving the Rebel Yell at a reunion. It sounded more like a series of barks than an actual yell.
A while ago, with much less information than what was on the Smithsonian video, the Museum of the Confederacy did some research. With only two authentic recordings, they used technology to create the voices of over a thousand men yelling that yell, and by God--it did sound just as eerie and strange as had been described by suddenly-nervous Yankees.
If you go to the MoC website (http://www.moc.org), you can get the CD they made of this effect. It is well done, and very convincing. Their historians must have been ecstatic when the Smithsonian video came out, verifying all their research and effort.
Confederate reenactors have been using the CD at their "School of the Soldier" gatherings to teach the authentic Rebel Yell, and it is easy to imagine the increase in magic moments when this wild war whoop comes over the hill at you, followed immediately by lines of butternut and grey, bayonets at the ready. EEEK!
The CD would make a great gift for the Secesh on your list--just sayin'