I'm digging the new Custom Domains service from Windows Live. Setup couldn't have been smoother:
The only even slightly tricky point is that I had set up a passport for harry@devhawk.net in the distant past and long forgotten the password. However, Custom Domains allows be to "evict" a user from the domain so I was able to recreate it with little trouble.
I do have two feature requests that I'm guessing are on the horizon for the Custom Domains team: