Short-cut you might not know in Ubuntu

nautilus / gnome:

ctrl-h : show hidden files

ctrl-t : move to trash

f9 : toggle side-pane

alt-home : jump to home folder

alt-enter : file / folder properties

alt-f1 : launch applications menu

alt-f2 : launch “run application” dialogue

ctrl-alt – right/left arrow : move to the next virtual desktop

ctrl-alt-shift – right/left arrow : take current window to the next virtual desktop

firefox:

ctrl-k : firefox search field

ctrl-l : firefox address bar

ctrl-pgup : next tab (left to right)

ctrl-pgdn : previous tab (right to left)

ctrl-t : new tab

ctrl-r / f5: reload page

ctrl-u : view page source

Source: http://ubuntu-tutorials.com/2007/02/20/shortcut-keys-you-might-not-know-about/