quantity option when adding to cart?

E-commerce site selling digicams, printers and media type stuff.
It has a shopping cart. Each product on the page has a little 'add to cart' button.

The question is, in this instance would you think it to be an advantage to have a small input box next to this button where you can specify the quantity?

On the 'vew cart' page where you would be taken after adding something there is of course the 'update quantity' option there anyway I just wondered if people consider it to be an advantage to specify quantity right then and there when pushing 'add to cart'?

your thoughts?

if its relevant to the item ... i.e. one may buy 100 blank CD's but probably not 100 CD burners (for retail anyway stuff anyway) ..in thats case I can't see how it would hurt, I did a similar thing on a site selling tickets for workshops etc and no one complained :)