If you use mod_gunzip, then you can store static content in pre-compressed form, and the server only uses (minimal) extra CPU if a browser doesn't understand compressed data. (Which is fairly rare these days - support for compressed data was standardized in the 4.x series.)

With mod_gunzip you're saving local disk space and activity, bandwidth, and not even taking up server CPU!

The catch is that this ONLY works for static content.

Cheers,
Ben