Bar code scanning using flatbed image scanner

I am trying to devise a system that needs to scan multiple bar codes simultaneously or one right after the other very quickly. I would like to keep it on the cheap side and use old USB flatbed scanners instead of buying bar code scanners.

So I guess my questions are....

1. Is it even possible to use an image scanner to read bar codes?

2. If it is possible, can one scanner be used to read more than one bar code at a time?

If anyone can point me in a helpful direction I would greatly appreciate it.

Thanks,
Nick