You can disable the forced capitalization with $wgCapitalLinks:

$wgCapitalLinks = false;

Docs for this & links to some related settings are available on mediawiki.org wiki: http://www.mediawiki.org/wiki/$wgCapitalLinks

Beware though that this will make the first letter of a title case-sensitive in all page links and URLs: for instance '[[foo]]' will no longer link to the page 'Foo', and '[[Foo]]' will not link to the page 'foo', unless redirects are put in place. Migrating an existing site can be tricky!

You can also use the 'DISPLAYTITLE' built-in parser function to adjust the displayed title to initial lowercase without altering other behavior on the site. There's a template on English Wikipedia which conveniently wraps it, which you might copy (requires ParserFunctions extension to be installed):

http://en.wikipedia.org/wiki/Template:Lowercase_title

-- brion

Thank you for good information, Brion. I see some pros & cons for both options. I'll test them out in a test wiki environment and make a decision.

Toshi