This is an excerpt from the ExtUtils::MakeMaker module. MakeMaker is the module used to generate Makefile.PLs for module installations. I prefer putting new modules in site_perl, myself, but if you want to keep your environment homogeneous, you could use the LIB attribute (I also include PREFIX 'cause you might find it useful):
PREFIX and LIB attribute
PREFIX and LIB can be used to set several INSTALL*
attributes in one go. The quickest way to install a module
in a non-standard place might be
perl Makefile.PL PREFIX=~
This will install all files in the module under your home
directory, with man pages and libraries going into an
appropriate place (usually ~/man and ~/lib).
Another way to specify many INSTALL directories with a
single parameter is LIB.
perl Makefile.PL LIB=~/lib
--
Love justice; desire mercy.