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Taming Your Multiple IE Standalones
Most of the conditional comment behaviors may be restored to the standalones by performing a simple one time edit to your registry. It consists only of renaming a particular key, which currently says IE, so that it says zIE.
To do this, click the Start button, click Run, and type in “regedit.exe”. […]

Another boss CSS example from ALA
A List Apart: Articles: Sliding Doors of CSS

display:none will make an element invisible for the most widely used screeen reader too. In fact, display:none will make an element invisible to everyone apart from source-reading propellerheads. Enter the aural text class.
The Aural Text Class

Clearing float container without source markup