The registrar badger.com (fairly new; they offered $8 domains on Hacker News last year although now they cost $10) has a concept called applications where they

The registrar badger.com (fairly new; they offered $8 domains on Hacker News last year although now they cost $10) has a concept called applications where they present a nice UI for 11 sites (including tumblr, heroku, and google docs). It makes DNS changes for you (and shows you what it will do beforehand) and in some cases tells you what you need to do on that particular site.