What's happening is these websites are reading your location and automatically choosing the best location for you. Stopping it is different for every website. I get the same thing here (located in Thailand).
For example, with Google, when you type in google.com, it usually directs you to google.co.jp, right? Fine, once it does that, look for the "Google.com in English" link, usually located to the bottom right. This will direct you to Google.com, in English, and it should always direct you there in the future (until you delete the cookie that tells it to do that).
I know MSN and Yahoo have language settings somewhere, I believe they're hidden in a little link on most pages or buried in the options somewhere. I changed mine a while back and don't remember the details, but they no longer come up in Thai. Some of them might have to do with where you told it you lived, so check that and set it to Canada. I know more than a couple did this to me and I had to set them to the US to get English.
Unfortunately, there are some websites that just don't give you any option. I guess they assume you are in Japan, so you must speak Japanese and therefore they force feed you that version of the site (Windows Live Messenger is guilty of this). As far as I know, there is no fix for this unless you do as Linux711 mentioned by using a proxy to make whatever service think you are somewhere you're not. However, in most cases, there is either an option on the main page, or it's buried in the options somewhere.
Toy around with it and see what you can work out. If you have questions about how to change the settings for a specific site, you could Google the site name and "language settings" or something. If you can't find anything, let us know and maybe we can find the answer.
