Now if you want rename your blog say from "inaction.example.com" to "takeaction.example.com", it's pretty simple.
- Create the new hostname in DNS,
- Add it as an alias to your apache config, <
- Create a soft-link to the current config using the new name,
- Edit the settings for your blog and give the new URL.
Edit: You can easily change the settings (from the last step) in the the db. If something goes terribly wrong, just poke around in there and update anything with the wrong URL.