That's a bit kludgy. Under XP, it's not so bad because the bar groups multiple windows for an application together, but try that under Win 98, though, and you'll see a different story.
Besides, changing tabs in Opera can be done with a simple keyboard shortcut . You could to change application windows, I suppose, but then you'd also have to cycle through any other open apps.
Sorry, I forgot that the psoting software would remove brackets (and text within them)... I meant to include the actual shortcuts: (CTRL+Enter) to tab between Opera tabs, (ALT+Enter) to switch applications under MS Windows.
Actually the 98 style would be more similar, being a list of them side by side you could access with a single click. WXP by default will stack them, which would require more than a single click to switch, but that is a start bar setting that can be easily changed.