You may have come to picture solar panels as rectangles angled toward the sun atop homes and businesses across the country. What you're picturing is most likely an array of silicon-based solar panels -- which come in two common "flavors," monocrystalline and polycrystalline. But next time you see such a system, take a good look... maybe even snap a picture. There's an emerging kind of solar panel that could soon make today's standard model look as old as your dad's Walkman: thin-film solar. There's been a lot of talk about this kind of technology lately, so we thought it wise to explain a bit about solar thin-film technology.