Question like this has been asked in SO before, and it seems it is not possible to grab the URLs opened in other tabs.
If you write blogs, then you could have seen the Preview button, which on click opens the blog post in preview mode in a new tab and each time you clicks that button the preview page which was opened previously get refreshed.
May be my question is not constructive, but I was wondering how they are capturing the tab and refreshing the page.
What kind of stuff they are using? If anybody got the knowledge, if you share it would be very helpful.
Update:
Firebugging reveals that the Preview is a button: