I am not claiming this to be the end-all-be-all solution, but here is the mod_rewrite I am using on Sillyness, werd that allows me to redirect all traffic coming into www.chrisjdavis.org and chrisjdavis.org to iam.chrisjdavis.org, but lets any traffic to www.chrisjdavis.org/something and chrisjdavis.org/something right on through.

Here is the code:

RewriteCond %{REQUEST_URI} !^/[a-z0-9] [nc]
RewriteRule ^(.*)$ http://iam.chrisjdavis.org/ [r=301,nc]

If you find this helpful great, if you can suggest an improvement by all means add it to the comments.