Recently I came across a really cool live server called "Custom Domains". This service is currently evolving into "Windows Live Admin Center".
What does it do?!
You get an e-mail server for your custom domain for free! You can then create up to 500 mail accounts on this service, each with 5GB storage. Neat, isn't it? For universities and schools you can even get more accounts if you register in the free program "Windows Live @ EDU".
So these are the 10 steps how to register your domain: