Sure:

http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html

But ofcourse only on the server....

oops... wrong button...

New client window: http://www.htmlcodetutorial.com/linking/_A_TARGET_95y98y108y97y110y107y.html

use the a4j:poll then... to periodically check the server.

check out ajax push as well: 
http://in.relation.to/Bloggers/UsingRichFacesPushAndDataTableAjaxKeysForPartialTablesUpdates

I'm interested in seeing a sample implementation for this solution with either push or pull approach.  This is an odd use case/request...

Here is the RF livedemo example for a4j:poll:

<a4j:region>
        <h:form>
            <a4j:poll id="poll" interval="500" enabled="#{pollBean.pollEnabled}"
                reRender="poll,grid" />
        </h:form>
    </a4j:region>

So how would you force a new browser window to open?  via JavaScript?  ok, so what event handler would you use in this case for a4j:poll?

So how would you force a new browser window to open? via JavaScript? ok, so what event handler would you use in this case for a4j:poll?

I was thinking about the oncomplete attribute and passing e.g. json data in the javascript function that you put in the oncomplete. But now I think of it, even if it might work on this level, the chance that a popup blokker prevents this is high. Opening e.g. a modal panel in which the user still has to click might work though.