The Warranty card does nothing. For service, you need a receipt from a authorized dealer (Like Adorama). You can toss the warranty card.
I know this is the case... but what is the warranty card... a vestige of years gone by? I had a 1.3mp Olympus p&s and the usb connection went bad, so I called them and they said that my online registration was for marketing purposes alone and I needed the receipt... I was so angry that I never considered another one of their products...
So if you have purchased from an authorised retailer - and why wouldn't you??!! - they should be able to take your zip code and / or email address at the time you placed your order, ID your order and send you a copy invoice.
If they can't, you should've bought from Adorama
This was in 2002... purchased from staples... and I believe that outdated the rewards tracking system... and I may have paid with cash...
I just bought a card reader and it was fine... but I guess I could have asked staples if the kept those kinds of records.