on Wednesday announced its SlipCover touchscreen system for the iMac. It turns an aluminum-clad iMac into a touchscreen-based system suitable for kiosks, point of sale systems and more. The SlipCover comes in 20-inch and 24-inch versions for $699 and $899 respectively.Troll Touch has, for many years, offered touch screen conversions for the Mac. The company’s systems utilize analog resistive touchscreen technology which let you input on the screen using your fingertip instead of a mouse. But typically the systems have required you to send your Mac in for conversion. The SlipCover is user-installable.Troll Touch continues to offer internally integrated iMac touchscreen versions, as well. Also available are touchscreen Cinema displays, MacBook laptops and other conversions.