Barcode scanning

How feasible is it to have barcode scanning function in a mobile tour guide application? I know technologies exist for taking photos of barcodes and getting price information via some back end database system.. but where does the analysis and decoding take place? and can it be done locally on the actual unit its self?

all I am hoping to do is have the user choose from a menu, take a picture of a barcode and then have the phone decode the picture and generate its own unique integer. This Data can then be used hopefully to navigate different menus..

I am fairly new to the world of mobile programming .. any thoughts or links to anything relevant would be much appreciated

.. its an iphone application using xcode

In my opinion it is not that affective, I used it in N82.