Wal*Mart has a pretty good deal going on right now for the Playstation 3. The chain is including a free $100 gift card with every 40GB Playstation 3 purchase.
The ad above states that the included card is a "Blu-Ray" gift card, which will only work in purchasing movies of that format. However, there have been plenty reports of people using the card for non-movie related purchases, so chances are the card will work for anything you want to buy. Best Buy is matching the deal as well, and I would recommend going there over Wal*Mart. Anyways, this is a great way to get onboard the PS3 bandwagon. I'm seriously considering it myself.