I've recently come across a bunch of useful flash posts from Strobist , Larry Becker, and bythom on Nikon SB-900, SB-800, and SB-600's and wanted to share them with you today.
First, the SB-900: "How to Use Your Nikon SB-900 in Optical Slave Mode" is a tutorial walk through on how to setup the built-in slave in a Nikon SB-900 speedlight. There are also pointers on getting better results when using any slaved flash.
Second, the SB-800: "Unlock The Superslave in Your Nikon SB-800" is a similar post to the one above but for the SB-800. You will want to check it out just to see the demonstration photo showing just how far it works outdoors in bright sunlight. I was also surprised to learn that it was not just line of sight, but that it works around corners too.
So what's the big deal about firing your flash optically? if you don't have pocket wizards (or have more flashes than pocket wizards) and want to fire your flash off camera it is a very big deal.
Third, the SB-600: This one comes from Larry Becker, he does a regular segment on DTown TV call "cheap shots" where he features tools and techniques that will help photographers do things for less money. Stretching your photographic dollar is always a good thing and I always pay close attention to what Larry has to say.
Larry loves his Nikon SB600's for a bunch of reasons, a big one is because you can buy it brand new for less than half of what the SB-900 costs. But the down side is that less money also means a few less bells and whistles. But as usual smart people always come up with great (and in this case inexpensive) workarounds.
So check out how Larry overcame the SB-600's lack of a sync cable port and built in optical slave.
You should also check out his blog in general as it is packed with good and useful information.
Finishing up with bits and pieces: You can read a comparison between the SB-800 and SB-900 here and a review of the SB-900 bythom here. If you head over to bythom you can find reviews and resources on just about everything ever produced by Nikon.