As long as you are asking for an idea, rather than a definitive answer, I will chime in here.

Two web sites, in two or more languages, do not constitute duplicate content, even if the meaning of the words is the same.

If you are using the same graphics on the different sites, I suggest that you translate the Alt text also.

Of course, you will want the title and other Meta content to be translated too.

I believe that the change in language is enough to satisfy the search engines.

In addition, the fact is that even if you want the different language web sites to say the same thing, they won't.

The grammar in different languages is different. Many words to not have an exact translation. Either way, the text will not be considered duplicate content.

On the other hand, a page of English text, is a page of English text.

qbania:

I may be wrong, but if the text of a web site is the same, I do not believe having .ca or .uk in the URL will make a difference. It will still be considered duplicate content.

I suggest that you forward the .ca or .uk domain, with masking turned on, to a home page in a directory on the main site, or even the main home page.

This will not be considered duplicate content because the page that the SE will see, will just have some meta text and a frame for the other page to load into.

I suggest that the meta data be specific to .ca and .uk visitors.

However, the visitor will see the .ca or .uk URL in the address bar.

The meta text will get the page listed in .ca or .uk specific search engines, although I do not know how they will rank.

I hope that this helps, and I am sure that more experienced people will chime in to correct and expand upon what I wrote.

Harris