Microsoft seems to have decided that if you want something done right, you have to do it yourself. The Remote Keyboard for Windows Media Center Edition (MCE) was developed specifically for PCs equipped with Media Center. (By the way, I don't know who comes up with the names for Microsoft's products, but he or she ought to change jobs.)
The idea behind this product is a simple one: to enable an MCE PC to be used in the living room with a large-screen TV or projector. But a keyboard and mouse are not really suitable for all Windows XP tasks in a living room; they're meant for a desk. So Microsoft came up with the idea of a portable keyboard that can be used from the couch, on your lap, fitted with an ersatz mouse. Obviously no one's going to try to do photo retouching with a keyboard like this, but for managing content, playing files, or Internet tasks like browsing, chatting or sending e-mail, it'll do.