Excellent question and there are as many answers as there are convention attendents. I used to photocopy my illegal club chip collection and other miscellaneous groups. Any chips for which there is a guide I would mark off in the guide which ones I had (you probably want the guide with you anyway so that you can "steal" that great chip that has $2 on it). My illegal club chip collection has gotten so big that I finally broke down and just made an excel spreadpage with enough description so that I won't get any duplicates. The main reason for not scanning and printing my collection is that it was taking a week or more to do the work and the four "books" that I made were costing about $35 in paper and ink. I have thought about putting everything on a laptop but it seems like that would be a lot of work and the more chips you buy the more work it is. I have been bringing most of my traders to the convention in a roll around suitcase which also holds my price guides. Remember that at the convention you will see over 100,000 chips. After an hour there you won't remember what is in your collection. After three days you won't remember what you bought that morning!