Ideas for a Handheld Portable Database Device?

Let me start with an explanation of what I do. I go to various places (pawn shops, Goodwill stores,clearance stores, etc.) and purchase used CDs and DVDs to resell. It is basically a side job for extra cash and something I enjoy doing.

I have a lot of CDs and DVDs that are worth nothing and it is impossible to keep all these items in mind when I go on a buying spree. So, my idea was to have a device that I can carry with me that I can access fairly easily to look up titles or barcodes and see if an item is in my "can't sell" or "can sell" list. Basically I need a portable database that I can spend the time to input what I currently have.

I don't want something that requires the internet. I had the idea this evening that maybe I can get a smart phone of some type without a carrier service. But I am not familiar enough with smart phones to know if there would be an AP that would do what I am talking about. And I don't want to pay a carrier service for a phone I'm not going to use as a phone. So with this in mind it has to be stand alone.

The main idea is "portable" and hand held. Something relatively small.

Does anyone have any suggestions? It doesn't even need to be anything too new. We could be talking an old technology that hardly anyone ever uses any more. And that would be ideal, I could possibly get it for a song.

By Suntydt from Tazewell, TN