Hey GG slow down.
I am not a real interanaut reaaly!
IE tab - - - que??
It puts a symbol on the status bar that , if you click on re-opens the current page using IE engine instead of Gecko also you can right click on a bookmark or link and tell it to open in IE tab. You really need to have FF on your M/C to play with to understand the nuances of add-ons etc.