Media::Type::Simple gives a simple functions for obtaining common file
extensions from media types, and from obtaining media types from file
extensions.

It is also relaxed with respect to having multiple media types associated with a
file extension, or multiple extensions associated with a media type, and it
includes media types for encodings such as gzip. It is defined this way in the
default data, but this does not meet your needs, then you can have it use a
system file (e.g. /etc/mime.types) or custom data.

By default, there is a functional interface, although you can also use an
object-oriented inteface. (Different objects will not share the same data.)

WWW: http://search.cpan.org/dist/Media-Type-Simple/