I did that for about 70 books recently. I purchased a scanner for very little (about 200 dkk, no idea what it would cost in USD), put it in the USB on my laptop

I did that for about 70 books recently. I purchased a scanner for very little (about 200 dkk, no idea what it would cost in USD), put it in the USB on my laptop and opened a spreadsheet. The handheld scanner automatially "enters" a newline once it has written the ISBN number, so the only thing you have to do is move onto the next book. You can scan books faster than you can pull them out and put them back. Actually getting the book info from the ISBN was very time consuming, I didn't know about Library Thing. You can almost certainly use a smartphone, but that will be a lot slower, comes with the risk of dropping it and then you don't have a bar code scanner left over for other projects.