how to enable keyboard shortcuts in google services

I love to use keyboard shortcuts while using my lappy.Using them in web pages comes with a problem though.This is not universal,i.e,there are some unique shortcuts for different pages.I am a person with an above average IQ but even then it  is difficult to remember all those shortcuts.Google understand this problem(thankfully!) and is trying to make the use of shortcuts easier.

Lets start from beginning.To activate 'keyboard shortcuts' in google services(like gmail,google reader etc),you need to go to setting>general tab>keyboard option.Select the shortcut on and save the changes.Now to use the shortcuts,here is the list--Keyboard shortcuts.

I was simply wary of the list.Now this is history.Google make the whole process very easy.Just press "shift and ?"(shift+?) and a pop-up like the attached screenshot will open.It'll contain the whole list of shortcuts along with an option to activate the shortcuts(no need to go to the settings page;this could be done from this pop-up only).

Thank you google.