Ever since I finished building my previous desktop computer, I promised myself that my next PC would have to be really compact, following the mini-ATX specification.
Then last month I found out that there exists a piece of eletronic device called Raspberry Pi that is very inexpensive, compact and energy-efficient. It can run several Linux flavors and it is not slow with its ARM CPU and 512MB of RAM.
I bought one for labbing and programming and it's proven to be very useful academically. You can actually run a 24/7 server with some services running on this little board. Here's the picture:
