in reply to Getting perldoc to recognize different perl versions
It searches @INC to find your modules. You just need to stuff your 5.00503 (or whatever you're looking for) directories into the @INC array before the 5.6.1 directories.
So to look at a module in the 5.00503 tree, you could do something like
perl -I/usr/lib/perl5/site_perl/5.005 `which perldoc` Foo::Bar::BazHope this helps!