It's so odd, I used to rank on the first page for my keyword and then I suddenly dropped out of the results (yea I know, I know, but bare with me). So I'm panicking a bit and realizing that this is apparently common, but then something funny happened - I checked the US results and sure enough I was still ranking on the top page for my keyword, but for every other country google.co.uk, google.ca, google.jp, etc my site is not listed for the keyword as far as I can tell. Also I'm searching the web, not the localized results and the server my site is hosted on in is in the Netherlands fyi. Are results that are not localized different, so searching for something on Google Japan will yield different results then Google.com or Google Canada? Again I'm not talking about localized results, as in searching for pages that are deemed from Japan, or from Ukraine or wherever. *I think I may have been penalized (still in the index of course, not banned) because on index page I have a link that changes the style of my page - so it's the same link but different css (and I think Google is penalizing me for having dupe content, even though it's my own site's content (on the same domain of course) - is that possible?)
Google Absolutely displays different results to different countries. TLD becomes very important when marketing to international locations. As for you * question; if you are only using css to change style options you need to make sure that google can't access the other pages through links. Nofollow will not be enough because the corresponding links still index. you need to add the noindex meta field to these alternate pages
I always get a bunch of Australian sites come up before the normal results, since I am in Australia. They seem to have quite a strong bonus.
the thing is that I was ranking across all of Google for the keyword, so previously all countries pretty much were the same, only recently does it seem to be showing only for the US version of the site.