This deal has ended.
Newegg has the 4GB Kingston Secure Digital High Capacity Memory Card on sale for just $9.49. Plus, shipping is free and there is no sales tax (except CA, TN, NJ). This SDHC card, which has a 4MB per second transfer rate, has received an average rating of 5 out of 5 from over 90 reviewers. It's also at Amazon for just $8.99, but unless you're a Prime member, you'll need a $25 order to qualify for free shipping.