You COULD try to install the module locally (in a specific directory) using a fresh perl install:

perl Makefile.PL LIB=/used/perl/modules/for/project
make && make test && make install
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The bundle the /used/perl/modules/for/project directory with you distribution and use lib for that directory. This might create unportable distributions for perl-only modules, and it certainly will create unportable distributions for modules build in XS, so watch out.

XML::Simple, by the way, uses XML::Parser, which uses the C expat library, which is not standard for most systems. You'll need to get the perl version, OS version, probably the C compiler, and all library versions correct if you want to copy the result of an install of XML::Simple to other machines. You might then even be able to use PAR to make the distribution. But probably not.

In short: installing != copying .pm files. That's why this whole Makefile.PL -> make -> make test -> make install thing is there in the first place.

For the XML modules, I think they are way too useful not to be installed anyway. Any decent hosting company should know that. Tell your clients their hosting company sucks. It won't help, but it might make you feel better :-)

-- 
#!/usr/bin/perl -w
use strict;$;=
";Jtunsitr pa;ngo;t1h\$e;r. )p.e(r;ls ;h;a;c.k^e;rs 
";$_=$;;do{$..=chop}while(chop);$_=$;;eval$.;
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