Every once in awhile, someone comes along and decides that the line between portable computer and massive screen needs to be smeared. During the Windows 8 device demonstrations we saw Steve Ballmer use the new OS on a screen the size of a wall, so it seems all too likely that someone would come along with a Windows 8 device packing a huge screen. This time Sony is stepping up to bat with the VAIO Tap 20 running Windows 8.Sony’s new “tabletop PC” is designed so you can either stand it up and use it like and all-in-one PC, or lay it down and use it as a massive Windows 8 tablet. When you want to stand the PC up, a large kickstand slides out from the bezel to support the 11 pounds that make up the Tap 20.The system is battery powered, so you can take your 20-inch tablet with you everywhere you go. Unfortunately, that battery is only good for about two hours. Once you get to where you are going, you can use the included wireless mouse and keyboard to continue using it like a normal PC.Aside from 10-finger touch support on the screen, the Tap 20 is NFC-enabled for data transfer. Sony is including several apps that are optimized for the screen size, like the family calendar app Fingertapps and the ArtRage Studio app for digital art. Sony has also included content from Sony Pictured Home Entertainment like the My Daily Clip trivia game. The Sony Mobile Bravia Engine 2, which is used in several of Sony’s new smartphones, helps the Tap 20 deliver a great viewing experience even when mobile.Sony is trying pretty hard to position this device as a computer for the family. Your kids can pick this 11-pound, battery-powered monster up and take it to their room and watch a movie, or it can be laid down on the living room floor so everyone can play games together. If it’s dropped, you’re only out $879 if you got the base model.As crazy as a 20-inch tablet/PC may sound, Windows 8 was built for exactly this kind of interaction. Windows 8 is the only OS that supports both a tablet form factor and supports multiple user accounts. In other words a 20-inch touch screen to replace the “family computer” is exactly what Windows 8 was made to do.