Doesn't work on Opera, Chrome and Safari.
For Safari, use Resize Safari Extension, it works great and offers advanced features such as "Offline usage", "Resize multiple tabs at once", "Reference book", "More customizable presets" and the "MoveTo tool".
Works perfect onFirefox and IE.
Yes, but only for a reasonable price. Don't even bother to ask me if you can't afford $20,000.