This site offers a free .htaccess generator based on an online form. Just answer some questions about how you want your .htaccess file to work, and it generates the file(s) for you.
You can set up serving of files based on time of day, custom error pages, deny access to e-mail harvesting programs, re-write virtual subdomains to a specific URL, force SSL and much more.
http://cooletips.de/htaccess/
