Note that we do not use locational meta tags (like "geo.position" or "distribution") or HTML attributes for geotargeting. While these may be useful in other regards, we've found that they are generally not reliable enough to use for geotargeting.
(from: Working with multi-regional websites)
Other SE might have a different view, Bing as an example.
It makes no real difference if you apply "country" as a location or a more specific physical address, see:
However, Google:
Other signals can give us hints. This could be from local addresses & phone numbers on the pages, use of local language and currency, links from other local sites, and/or the use of Google's Local Business Center (where available).
So signals (a combination of your localization efforts) are the way to go. Use rich snippets or take a look at the microformat location efforts to be at the front of parsable address and location information, along with external links from localized sources.