This apache's module detects the browsers capable of decompressing
the objects on the fly and applies compression to pages, etc. sent
to those browsers. This includes dynamicly generated content too.

Due to browsers' bugs or for other reasons (gzip-ing a typical JPEG
file is silly, for example) you may wish to disable compression of
some MIME-types and mod_gzip allows you to do that.

WWW: http://www.remotecommunications.com/apache/mod_gzip/