Take your Wordpress blog offline with this Maintenance Page Plug-in
Use this plug-in when you need to perform code changes, updates or edits to your Wordpress blog and you don’t want your users to receive error pages or pages loaded with garbage code. This is very clean and professional method of performing maintenance. I have’nt used this plug-in so I can speak to its functionality but may in the future.
Note: According to the Author, this plug-in sends a 503 service unavailable for feeds and trackbacks stating that the service will be available in X. X is set by the admin. WordPress endorses this plug-in.
