A friend asked me to be the photographer at their wedding since their original photographer bailed. He's seen my work so he knows I can produce quality work, dispite the fact this is my first wedding or receiving any compensation for taking photographs. I know I'm going to need a few things in the equipment department.....I'm thinking another lens and maybe something as far as helping out the lighting situation in low light reception areas. In addition to the extra battery, about 10-2 gig SD cards, what else is basically essential for a successfull shoot? My equipment now is a D40x with Sb400 speedlight Leses are 18-55 mm f/3.5 55-200mm f4 If I could add one more lens to the mix, which should it be? And what should I do about lighting? I know the sb 400 is ok, but is it enough to do the trick? Thanks for any help in advance.