I use a little program called Kill Popup 1.2. You don't need admin rights to install it (it doesn't modify the registry or anything - just copies to C:\Program files) so it can be installed anywhere.
It is a 'dumb' popup blocker. That is, it blocks all
popups regardless of if they are ads or valid popup windows (such as a PM on here).
To allow a popup to occur you just hold down the CTRL key and it allows the popup to go ahead. You can also disable popup blocking by clicking its icon in the system tray.
There are times when it does let popups through, but that's life. I'm yet to find a perfect blocker.
Get it here:
BTW, thanks for the popups from that site you posted, XA!