Matt Cutts Gives Tips On Moving Sites & Keeping Google Happy

Google’s Matt Cutts has moved his blog to a new host, and he shares some
advice on how to keep Google happy if you have to do a similar move
here. The
last step is most important. Once you are sure Googlebots are visiting the new
site and not the old, it’s safe to shut things down. He also touches on what do
to if you need to change domains (short answer, 301 redirect from old to new).
By the way,

Retaining Traffic after a Web Site Redesign from SearchDay last year has
some related tips you may find useful.