I found this post on Life Hacker about ‘future proofing your e-mail addresses’. This is one of the frames we use to talk about digital identity too. They have a bunch of tips and in the comments someone pointed to this service Net Identity.

They lease out sub-domains of popular last names; i.e. john@smith.net . While you don’t technically own the domain, its a great half way for people who dont need a website, but are willing to pay for an easy to remember name. Although they also do offer a matching website, www.john.smith.net. Ive been using them for over 4 years and love it. They offer POP3, webmail, and other goodies for about $30 a year.