Pressing alt then scrolling with the mouse used to give me a transparent window, is there any way I can get that or something similar in Ubuntu 12.4?
Install these pacakges with this commands
This will install the compizconfig-settings-manager, you can find this by searching as
Open the compizconfig-settings-manager by typing
This should automatically enable the plugin, if it is not, press ALT+F2 and type
Now you can increase or decrease the transparency of any window by holding the ALT key and scrolling.
Hope this will help.
Note: If Unity seems crashed, don't be bothered. ress CTRL+ALT+Del to bring logout window, and logout from your session. Then login again.