There's a very straightforward web based solution over at ISBNDB.com that you may want to look at.
Edit: Updated API documentation link, now there's version 2 available as well
Link to prices and tiers here
You can be up and running in just a few minutes (these examples are from API v1):
The results=details gets additional details including the card catalog number.
As an aside, generally the barcode is the isbn in either isbn10 or isbn13. You just have to delete the last 5 numbers if you are using a scanner and you pick up 18 numbers.
Here's a sample response:
The Joy Luck Club
Amy Tan,
Penguin (Non-Classics)