Yep, click the "Metric" link at the top-left of any page. That will switch the entire site view into metric units. There's a little more info in the FAQ.
Naesstrom, yes if you switch views the links to RSS feeds across the site will change to the correct feeds for your view. If you're already subscribed to a particular feed, you'll need to switch views, click on the new feed link and resubscribe.