you can use 1 account to claim multiple cases but the Case Program APP needs to be installed on each individual IPhone, Apple ships it by using each IP4's Unique Serial Num.

But you do know right that the Case Program is over on the 30th September?

My bad you guys are right and apologies for my earlier post
FROM APPLE WEBSITE

We now know that the iPhone 4 antenna attenuation issue is even smaller than we originally thought. A small percentage of iPhone 4 users need a case, and we want to continue providing them a Bumper case for free. For everyone else, we are discontinuing the free case program on all iPhone 4s sold after September 30, 2010

For iPhone 4 purchases made before July 23, 2010, you must apply no later than August 22, 2010; otherwise, you must apply within 30 days of your iPhone 4 purchase. To qualify for this program, you must purchase your iPhone 4 by September 30, 2010.

This is how it works:

Apple will send the case for any Iphone's purchased before September 30th which must be activated via ITunes by the 30th.

For example if you'd purchased your IP4 say September 28th. If its activated after September 30th you wont qualify for the Case Program. Those who have purchased it before the cutoff date and activated their IP4's will qualify and have 1 month period for them to claim the free case.

Apple checks for the eligibility of the each iPhones using its serial num and activation date

I tried to download to itunes but the link is no longer works. U download fr which country? 

Anyone have the claimed incase Snap case on their iphone 4 currently?
Will you still see the metal band from the front?
coz I am not sure my unit have visible metal band from the front, not sure cause by the case itself or cause by 3M carbon sticker I stick behind.