I did a thing like that once. There's a bettr way that I didn't think of at the time, though: Iframes. Popup blockers don't work on them, and they aren't intrusive.
You can creat an IFrame with
var x = document.createElement('iframe') and use
x.setAttribute('src', 'URL') to point it correctly. You may need to append it to the document with
document.body.appendChild(x), but that may not be necessary. If it is, you should probably set the width and height to 1 so that it isn't noticeable. I think the new page can then be accessed with
x.document, which of course can be traversed to find your info in the same way you can traverse any other document.
^D
$ shameless-plug
http://line-ed.sourceforge.net
