PPCGeeks - barcode reading solution?

I have a friend who uses a handheld USB barcode reader at home to scan
books and automatically look them up on Amazon, to see what they are
selling for. She would like to be able to do this from anywhere with a
mobile device. I'm not sure what the best solution would be for her.
Here are some possibilities:

1. Dell Axim X50v - I have a spare one of these and thought I could
get an SDIO barcode reader to plug into it. The main drawback is that
is uses only wifi and not EVDO, so she would have to be near a wifi
hotspot in order to connect to Amazon to lookup the books.

2. PocketPC - I have an old Verizon XV6700 that's seen better days,
but still works. If I could find barcode reading software that can use
the internal camera of the PPC, she could use that with a data-only
plan to connect to Amazon.

3. SmartPhone - I like this option best, as she would need only one
device. If she upgrades her current phone to a SmartPhone AND I can
find barcode reading software that can use its internal camera, then
she will be set.

Does anyone know of any barcode reading software that runs on WM5 or a
SmartPhone? Does anyone have any other thoughts or ideas on this?

Thanks,

Mike