The Raspberry Pi is quite a nice project. It allows tinkerers and hobbyists as well as professionals and companies to quickly build applications that interact with the physical world for a very affordable price (a Raspbery Pi computer can go for like 30 euros). For example I have built an automatic hard disk cleaner with a USB hard drive dock and a Raspberry Pi. Just plug a drive in and it securely cleans it. Another project of mine uses little infrared transmitters to send out commands to my airconditioning units and window blinds. It is able to learn new signals from just about any infrared remote control, and reproduce them on command. I have made other projects based on a Raspberry Pi, both for personal hobby and for professional purposes. These I have on my site with some details;