I was thinking today about my collapsing side-bar, which I implemented in Collapsing Blue wp-theme.
You don't see it when it's collapsed, but it still loads in hidden DIV.
If a user wants to hide it, then it is not needed for that user.
Then why wasting bandwidth and server recourses with this user if we can save some?
It is also not good to load Google ads if the user don't see them and don't use them.
The solution is easy.
I just had to make check for the cookies and not to load the code of the side-bar if it is collapsed.
You can test it on my side bar.
Collapse it and load another page.
Then open it: empty.
A small message is telling you that the side-bar will load on the next visited page or on "Refresh".
Not bad idea, eh?