This is a quick article on how to work around the "Another blog is already hosted at this address." error while setting up Blogger for use on a custom domain.
I had been using iWeb to publish my photos to benmctee.com. Since switching over to using Linux (Ubuntu) on my MacBook and after finding out how easy it was to post pictures using my Droid and Blogger, I decided to go with using Google's services for picture posting vice Apple's MobileMe services (also, I no longer use the iPhone).
Several things need to happen in order to successfully switch over the domain hosting on Apple's servers to Google's servers. Since my domain was already purchased, this was a lot more difficult. My recommendation for anybody wanting a personal domain for Blogger posting is to purchase it through the Blogger web site and your Google Apps will come already set up for you (or so I've heard).
1. Go to your domain registrar, (I used GoDaddy) and create (or change if already existing) a CNAME named "www" and point it to "ghs.google.com". This change may take up to 48 hours to propagate they claim, but mine took approximately 5 minutes.
2. Log into Google Apps for Your Domain or create a new account if you do not have one.
3. Once logged in, from the Dashboard, go to Sites > Web Address Mapping > Add a new address. Make this go to "www.yoursite.com". Allow a few minutes for this to propagate throughout the DNS settings.
NOTE: At this point I went to www.google.com/sites and created a simple blog site from a template that went to www.benmctee.com for testing. Once I figured out that all DNS was set up to go to www.benmctee.com, then I could go forward with my Google Apps / Blogger settings.
4. Back on the Dashboard of Google Apps for Your Domain, go back to Site Mappings (Service Settings > Web Address Mapping > remove the www.yourdomain.com mapping. Also, now would be a good time to go back to www.google.com/sites > Your site. On the "More Actions" pull-down menu, click Manage Site. Once there, under Site Settings > General, scroll to the bottom and click "Delete this Site". Now you should be ready to redirect your traffic through Blogger to your Google Apps page.
7. Go to your blog on blogger.com, login, go to Settings > Publishing > Switch to Advanced Settings > Custom domain name.
8. In Your Domain, type www.yourdomain.com. Once you Save Settings, a checkbox will appear to redirect yourdomain.com traffic to www.yourdomain.com. You will want to check this box and then resave your settings. This allows people who only enter your domain without first entering the www. subdomain to still see your site.
9. Wait a little bit of time for all of your settings to propagate to the DNS severs, and everything should work properly.
This process was a span of about 3 days of research for me. Hopefully with this info you'll get your site up in a couple of hours. If I have missed anything or you experience other difficulties, please leave a comment below.