I guess it might be worth noting a little caveat here that has caught innumerous novices in their first brushes with perl.

Many people tend to forget in the heat of the moment that $# gives you the last index of the list - not the number of elements in it.
Because of this: $#list won't give you the same result as scalar @list.
This, I will admit, caught me a fair few times when I was starting out.

Just a simple thought, probably beneath most of you guys out there, but one worth remembering ;)