I didn't see this mentioned yet, so I apologize if I just missed it...

You can program in a Perl style that detects mispelled subroutine names at compile-time. This requires that you pre-declare all of your subroutines¹ and then never use parens when you call subroutines.

This, of course, doesn't work for method names. Compile-time checking of method names is nearly antithetical to Perl 5's OO system. (:

¹ Well, you could probably instead topologically sort your subroutines, but I wouldn't recommend it.

                - tye