What are you doing this summer? If you're considering a conversion of your card files to a database, take a look at RFID. Barcodes are great, but they don't check themselves out or help you to find a mis-shelved book. RFID is more expensive than barcodes, but when you consider that most of the expense of a conversion will be in labor, the extra costs will probably be acceptable. You'll certainly earn back the cost in cost savings.
TAGSYS RFID: leader in RFID asset tracking: "TAGSYS provides end to end RFID systems to track items. TAGSYS RFID automates manual processes, authenticates goods and enables real-time inventory."