To access the engineer menu, press the dialling button on the main screen then key in 3845#*910# and the menu will appear, I recommend you don't mess with anything unless you fully know what you are doing, these menu items do not follow conventional menu rules in that most of them contain no 'back' button, and sometimes there are 2 choices of setting where 'ok' and 'back' would usually be, which will change the setting, and you do not know which is the default.
Choosing 'Fake Language' changes everything into programming terms for the phone, eg 'my images' becomes 'menu454' (or something), I don't know if you can reverse this by choosing another language in normal mode or resetting in normal mode, but I reversed mine by resetting from this engineer menu, as I needed to fix what might be my operator's attempt to slow down my HSDPA.

You might be able to enable it by changing your firmware to an open/unbranded one, I am still learning about modding so I don't know where to get one or how to install it though.

I was messing around in the engineer menu and found that to go back when there was no back or return icon, just press the shortcut button. (between call and end call) =)