I am going to create a new Virtual Machine running Debian Lenny. I want to install the latest stable version of Perl (5.10.1) such that all non-root users would use it by default. However, I don't want to mess up the system perl.
I found a solution: How can I install a separate perl without disturbing the existing one?. I guess that I just didn't use the right search terms yesterday.
See perlbrew by Kang-min Liu. It allows you to easily install multiple versions of perl without disturbing the system perl.