how do I change the way file/folder mouseover metadata is displayed?

Ulimately, I just want folder size to be displayed when viewing in details mode but it seems that isn't an option with windows 7 so the next best thing is when you hover the mouse curser over the file and the metadata pops up (I think it's called tooltips) with the file size in it - but this is a right royal pain:
firstly, it takes way too long to pop up - I want it to pop up intantly.
secondly, it pops up when you don't want it and when you do want it, it doesn't always appear and you have to move the curser back and forth and click in the window and move it over again and finally you just have to right click on the file and select properties.

What would be ideal is for the pop-up to appear instantly on mouseover but only if I'm holding down a control key.

does anyone know if this is possible to do or how to go about configuring it?

Thanks.

This will be interesting as I have also noticed when I mouse over a (wanted) file for the tooltip info nothing happens until I mouse over another (unwanted) file and then go back to the original file.
That's a real PITA when its the only file currently in the folder! Then as you say, you have to open the properties. It doesn't always happen that way though. It just seems to sense when you are in a hurry!

I found out how to disable tool tips altogether:

1. Go to Start > Run, type regedit
2. Scroll down HKEY_CURRENT_USER > Software > Microsoft > Windows > CurrentVersion > Explorer > Advanced
3. You will see an entry named ShowInfoTip. Click modify and set its dword value to 00000000
4. Exit and reboot.

But not how to adjust the timing and whatever reasoning it has behind deciding if it should appear or not.

Should've put this in my first post!!

Code:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Control Panel\Desktop]
"MenuShowDelay"="40"

The default is 400 or 0.4 secs, but, as you say, it doesn't speed up a "no show"!!

I just tried out changing the "MenuShowDelay"="40", and rebooting, but it didn't have any effect.
Do you know if, once we find the right section to edit, if it's possible to bind a key to it in order to toggle it on and off?