What's the best tool for keeping track of inventory

I have all one-of-a-kind inventory, and I am struggling to keep track of it. I currently use an excel spread sheet, and have long descriptions of each item and I have about 300 items. Once I expand and have thousands of items in inventory (all different) is there a better way to keep track of this?

Unfortunately, there are few packaged applications for tracking unique inventory, since for most businesses, this is a non-issue. However, you are not alone - artwork (and other similar products), telecom (phone numbers are absolutely unique), lotteries - all require similar functionality.

If you grow large enough, it may be worth your while to invest in a custom inventory management system, which is basically a database with the ability to group products (e.g. in telecom, there might be categories of plans, unique phone numbers, etc) and the ability to have unique products. As far as I know, there really isn't anything out there that can do this, other than a variety of custom tools that you the author may have published online.