If you want to maintain your SEO and search engine stats for the pages you moved, I wouldn't do a META redirect. Instead, you should do a 301 redirect, which is usually the correct way to say to a Search Engine the page has moved.
If the site is hosted on Apache, you can do this in your .htaccess file. The command would be something like:
redirect 301 /page.htm
http://www.domain.com/page.html. More on that at
http://www.isitebuild.com/301-redirect.htm.
Alternatively, if you've moved a number of files or there is some pattern to the files which have been renamed, this could be achieved through a mod_rewrite rule.
-Matt