If you have tried Firefox in windows ;) you have noticed that the ubuntu Firefox does not use backspace to go to the previous page you can change this by doing the following :
1- open you firefox browser. 2- in the address type [COLOR="Red"]about:config[/COLOR] it will give you a notification message click [COLOR="Red"]i'll be carefull, i promise![/COLOR];) 3- type backspace and press enter key. 4- the search result will be : [COLOR="Red"]browser.backspace_action[/COLOR] click on it and change it's value to 0 (zero)
and you are done now enjoy the backspace. ;)