Basic content negotiation to eleminate file extensions

What is needed in .htaccess?

[anax]

This recent thread got me thinking again about starting to eliminate file extensions as recommended by W3C:

[webmasterworld.com...]

Server-side stuff is pretty obscure to me, but I do know how to cut and paste things into an .htaccess file. If I want to start simple (not worrying about things like alternate language versions or different image formats) and just want to be able to replace "filename.html" with "filename" everywhere on a site, what's the recommended method? Can it be done with something added to the .htaccess file?