Mark, personally I use binders and the same holders Jim Munding uses--from one of the warehouse retailers (Staples, Office Depot, Office Max etc.) $2.25 for a pack of 10 pages. At 20 cards per page (front and back) that's enough to hold 200 cards.

I then put them in binders separated by states. Just before a major show, I will photocopy all of them (in color,) bind it in my own folder, and have it available so that I don't buy or trade duplicates. This way, I know what I already have.

That and Pat's book is all I need to take with me, except for my traders ---which can number into the thousands.

In case you are interested, I do specialize in Reno cards and keys. As soon as Allan Anderson lets us all know about the new releases, Bill O'Day and I are off to Reno to get them.