here's my FBO items list for wedding day...
1) 01 x Body, Main : D100+MB-D100
2) 01 x Body, Backup : F100+MB-15, + a few assorted rolls of film
3) 01 x Flash, Main : SB-80DX
4) 01 x Flash, Back-up : Yashica CS-220 Auto (alternatively D100's built-in popup flash)
5) 02 x CF cards (512mb + 1gb)
6) 04 x Sets of rechargeable AA batteries (04 batt per set) + random sets of alkaline AA batteries.
7) 03 x D100 battery (01 x original, 02 x 3rd party)
8) 01 x AA battery tray for MB-15 (in case 3rd party battery decides to screw up)
9) 01 x External light meter (01 x Sekonic Digilite F, bring for show only)
10) 01 x Set of misc. lens/camera cleaning kit (aka First Aid kit...you never know when you need it)
11) 01 x Lens, Prime : Nikkor 50mm f/1.8
12) 01 x Lens, Prime : Tamron 90mm f/2.8
13) 01 x Lens, Zoom : Sigma 17-35mm f/2.8-4.0
14) 01 x Lens, Zoom : Tokina 80-200mm f/2.8 (very seldom take this out)
15) 01 x Computer, Laptop (only on certain occasions)
16) 01 x Full pack : Lowepro Stealth Reporter 650 AW