More like how many bags do you have!! An outing would be:
Nikon AF-S DX 18-55mm 1:3.5-5.6G (sluggish but great optics)
Nikon AF-S 60mm micro 1:2.8G (a must for insects!)
Nikon 35mm 1:2.8 manual focus (a heavy little old gem)
Vivitar 75-300mm manual focus (hooked onto belt loop, not in bag!)
lens cleaning stuff
Also in the bag:
Vivitar skylight filter (nice effect that I usually forget to use)
1. My wits [or lack of it]
2. D90 + lens- 60mm macro & 12-24 is standard packing.
3. 2 SB 800's + cable and or SU800 + GF diffuser cups
4. Lowepro AW Trekker bag that's too big with stuff in it-water bottle, snacks, etc.