Binding? Dunno about that. Spining yes. And recommended.
The spine of the shaft is the bend of the shaft that gives the most true path of bend, or the axis in which the least amount of deflection are noted. Basically, if you took a shaft and bent it one way, it's bend would be more inconsistent than if you found the spine of the shaft and inserted it into the clubhead with the spine facing the target (if you're looking at the club as a right handed golfer from the butt of the grip, it should be placed at either the 9 or 3 o'clock position to maximize the natural spine of the shaft.)
Some shafts are better than others. Steel can have super tight oscillations, and it can be way out of whack too. Graphite shafts are best influenced by the spining.
Cost is about 10 bucks a shaft. You can find pre-spined shafts for a steal, however.
I had my Driver shaft Pured by Golfsmith. I can say that it makes a huge difference, as I hit the same club with the same shaft and couldn't nearly hit it as consistent.
Check out the SST Puring process done by Golfsmith for more information. Or go the the SSTPure website and get all the details. Personnally, I wouldn't build a driver or wood without have the shaft aligned. As Rockford35 posted, it make a big difference and I'd recommend it to everyone except your playing partners.