Porting your studio

Since I shoot on location and travel to my shoots in most cases, I specialize in setting up on location. My stripped down travel gear usually includes the following:

2 AB800 Strobes
SB-800 Speedlight
2 shoot through white umbrellas
2 reflective silver umbrellas
a set or two of multi-colored gels for the strobes
A few light-sensing slave attachments for my hotshoe mount flashes
48" pop out reversible reflector
24" pop out reflector
A bunch of heavy duty light stands
As many heavy utility clips and small plastic clips as I can carry
Rope (just in case)
Plastic bag (I don't like my camera getting wet)
A C02 compressed air cleaner
A grey/white/black card
A Lumiquest flash attachment to hold gels for the SB-800
Misc little tools and clamps for modifying and holding gear

That's a rough overview, and it has worked well for 1-2 person shots. For groups you might want a little more power and light, but it will do in a pinch.