MegaMacs offers the Kensington Contour Terrain 15" Notebook Backpack, model no. K63102US, for $16.49 plus around $8 for shipping. That's $30 off and among the least expensive Kensington laptop bags we've seen. It features water- and stain-resistant canvas construction, DropShield-padded accommodation for up to 15.4" laptops, elastic expansion bands, side pockets, and more. Deal ends September 5.