If you're in the market for some wild and snappy backgrounds for your Web pages, slither on over to Reptile, home of a freeware application that enables you to decorate to your imagination's limit of shapes and surfaces — all in your choices of colors. Choose from wavy, bubbly, organic, big, small, wide, narrow, rough, or smooth textures for your Web page backgrounds, your Windows desktop, or your own inventions. The site carries a few words of warning to its visitors: "Reptile is so much fun to use, it is difficult to stay focused on what you want to do . . . this program is addictive!"