B&H has a solid deal on two or more Sony 16GB Class 10 SDHC cards priced at 2 for $15. Additional cards are only $7.49 after that.
Use the quantity box to select more than one (see above image) and you’ll see the discount in your cart. Check it out here at B&H Photo.
Class 10 cards deliver on speed for HD video capture, which goes along with the size advantage of the SDHC spec. For more details on what all the classes and card specs mean, check out my resource article Demystifying SD Cards.