Open source media center for Windows…
Why buy a Media Center PC when you can make your own – fun project for an old PC “MediaPortal turns your PC in a very advanced Multi-Media Center / HTPC. It allows you to listen to your favorite music, radio, watch your video’s and DVD’s, view, schedule and record live TV and much more. You get Media Portal for free/nothing/nada/nopes and best of all it is opensource. This means anyone can help developing Media Portal or tweak it for their own needs! “ [via] Link.
Here’s a really good example of what you could do with an old Apple Mac G4 cube – build an aquarium inside of it! This project was inspired by 
Nonstopmac writes “This article will show you how to easily setup a free DNS service that will give your Mac computer a static hostname. There are a lot of possibilities you can use this for, as most of the Internet connections offer dynamic IP addresses. Having a dedicated hostname can make it easier to remotely connect to your computer and run any kind of server.” 
Could be a fun MAKE project…“Cuckoo IP is a voice messaging system. The clock’s answer phone can be dialled from mobile or landline. Leave a voice message, select a time for the delivery of it. At that time, the cuckoo will emerge from the clock and broadcast your message. The device uses networking protocols to communicate with a server. Every minute, the clock asks the server if there’s any message for that time-slot and request the sound file.” 
“The Bell Model 500 desk phone manufactured for decades by Western Electric is an icon of Twentieth Century product design. The evolution of the Model 500’s receiver begun with the first telephones produced in the late 19th Century and it’s longevity has taken it into the 21st. I have always found it to be ergonomically designed and comfortably to use, It is the embodiment of “form follows function”.” Here’s how to make it a cell phone handset. Thanks Jake! 
Wow, this will likely be commonplace in just a few years…“Build a low-cost, terabyte-sized backup server using Linux and back up your digital audio files, digital images and digital movie recordings. A terabyte-plus backup and storage system is now an affordable option for Linux users. This article discusses options for building and configuring an inexpensive, expandable, Linux-based backup server.” 
Bill writes “When I saw the retro-phone handset on thinkgeek I knew I wanted one. Then I realized they wanted $30+ for it, and I thought to myself — I can build that. So after some cutting, testing, and building I have finished my Retro-Cell phone handset, and I will show you how you can build your own for under $10.00″