SaraAB: If they are indeed on sale at Staples this week, the sale should be reflected online as well.
I just picked up a 4GB SanDisk Pro Duo from the closeout at CompUSA. The markdowns are now at 60-80% off. Memory cards are currently at 60%, and it was originally $100, so I got it for $40. At the CompUSA here, the discounts will be 70-90% on Sat, and then maybe higher on Sunday when they close for good, so it might be worth people's time to check it out over the weekend.