Mid Pass Filter
Mid Pass Filter is a new CSS hack by Tantek Çelik. This hack is a filter that targets only version 5.x Internet Explorer for Windows browsers:
The mid pass filter can be used to import styles exclusively to IE5.x/Windows to apply either before or after other style rules, as demonstrated by the style sheets midpassbefore.css and midpassafter.css.
This should be useful, but I think I’ll play it safe and wait a little before using it on any client websites, just in case there are problems that haven’t been discovered yet.