While I usually host the games, recent events have made it neccessary for me to be able to transport the game supplies to other locales.
Basically, I found a relatively sturdy piece of inexpensive wheeled, hard sided luggage, into which I pile 6 Chessex minis boxes, a seperate box for the party's minis, a shoebox of Huge minis, the required books (Core + Completes for the 3.5 game, Core + Classbooks for the 3.0 game), 2 large bags of dice, 2 calculators, and a set of pliers (for loose mini bases).
And I have room left over.
It has reduced the number of trips from car to house (and vice versa) from 3+ down to one.
The only thing that doesn't fit in the luggage is the battlemap which is carried in a long grey tube with a shoulder strap- they sell them in art-supply stores, and are infinitely expandible.
The only real problem I have is that I generally carpool to one game in an SUV, so that lift in and out of the car can be tricky at times.