I'm currently writing an app to do this, using the camera to do the scanning. I've been learning GTK+ and the C interface to SQLite along the way, so is still work in progress, but the code compiles and hopefully gives a decent idea of what I'm trying to achieve.

See https://garage.maemo.org/projects/maemo-barcode/ and specifically the branch I'm working on atm: https://garage.maemo.org/plugins/scm...=maemo-barcode

Using a plug-in scanner as well/instead shouldn't be an issue and I'd like to include this (if you find a cheapish scanner do let me know; life will be easier with the higher quality and pointing outwards camera on the n900).

My plan is to let the user create different tables in an SQLite database (e.g. shopping list, DVDs I own, Books I own, Books I want, DVDs I want, CDs, etc.) so that the user can do a couple of things:

Have a list of the DVDs/CDs/Books they own, so they can check in the shop to see if they're going to buy something they already have (I have this problem with books and DVDs, because I have lots of the former and because I don't tend to watch the latter often enough to remember what I do have).

If the book/DVD/CD in question is not in the db (i.e. you don't own it), allow the barcode (and metadata obtained from the barcode, e.g. isbn from barcode) to be saved and looked up (I need to write some code for a backend server or some web trawling code for the app on the device) to fill in the details of what the item in question is. There are a number of online services which allow this, iirc I left some notes in the source (see above).

I also plan to allow text searches of this data (i.e. the databases will be populated with the barcodes and then these can all be looked up when a connection is available and then the db can be searched using text strings too, just in case the scanner doesn't work/someone asks you a question without giving you a barcode).

Looking at the web trawling, I want to do similar to the Android competition winner Android Scan (http://scan.jsharkey.org/) and once a barcode has been scanned it will be looked up (i.e. fill in desctiption) and also have prices and locations downloaded so you can see if it's cheaper online, etc. This will be easier on the n900 as it will be always connected.

Last but not least are different types of barcodes, 1D stacked, 2D (QR code, Datamatrix) which can store text, urls, etc. We've been working on getting these to be decoded in realtime, and would like to add these in so people can scan them and use the data contained therein (e.g. display/save text, open url, etc.)

I hope that makes some sort of sense