If I do a perl -v at the shell prompt it still gives me version 5.6. First off how can I have the system recognize perl 5.10 as being the active version of perl (if I wanted or needed to)?

When you ask a shell to run something, if you don't specify its location, the shell tries to find it by searching the list of directories in the $PATH shell variable. It runs the first thing it finds that matches what you asked. If you type /opt/.../perl -v at the command line, you should get the answer you are looking for (replace the ellipsis with the rest of the path to the new Perl binary).

In a script you can get the same effect by using "/opt/.../perl" on the #! line (rather than /usr/bin/perl).

It is generally a bad idea to modify system paths to interpose your newer Perl before the default Perl. This has the potential to break important parts of the operating system that blindly assume the presence of the Perl that came with the operating system. It is also possible to create problems if you modify your personal path, but these would likely be easier to fix.