I am a total newbie when it comes to flash, and I am looking to buy an off-camera flash for my Nikon D80. The main choices for an amateur like me seem to be the SB600 and SB700. What are the main differences between the SB600 and SB700 flash?
(For example, the SB600 has a slightly higher "guide number." Should I care? Does it make a practical difference? If I some day decide to use a multi-flash setup, will there be limitations? Anything else I should know about?)