directrix - 3:40 pm on Oct 13, 2005 (gmt 0)

You can configure Opera to display window size, and then size it accordingly. Under Tools > Preferences > Advanced > Browsing, check the "Show window size" box. (That's on 8.50; I think it's similar on earlier versions.)

I've found that the dimensions are accurate, but beware that the height includes the toolbars. (i.e., the dimensions are of the viewport.) So you may need to copy the screen image into Paint, or similar, to check the dimensions, and then adjust for the toolbars.