IE View is one of the cool free firefox addon which allows you to open any web page you visited with firefox to be opened in internet explorer. You can open any page in internet explorer from firefox just by right clicking the page and select View This Page In IE
IE View adds the menu items to the context menu and the link to the context menu. Right clicking a link now includes "Open link target in IE" menu item and Right-clicking elsewhere in the main body of the page (not within an image, text box, etc.) gives "View this page in IE."
Moreover you can still configure this addon to open specific sites always with internet explorer, this could be really best option if you use firefox as a primar browser but may want some sites or other urls to be opened in internet explorer only.