.htaccess SEO trick: 301 redirect instead of 404

Update on 7th August 2013: According to Google this doesn’t work anymore, see (around minute 22) http://www.youtube.com/watch?v=WsDeu5PUx2A

However I’m not sold on this and doing a test.

Bought a dropped domain?

This is how to redirect all the link juice to the homepage:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule .* index.php [R=301]