Creating a secondary functional interface (like what CGI.pm does)

I don't like this at all. If you want to provide a secondary functional interface, please add a Foo::Bar::Functions or Foo::Bar::Simple module or some such instead. That way, the baggage doesn't have to be dragged around by everyone who probably doesn't even need it, nor adds extra mess in the main module to maintain. It also, and this I consider the greatest benefit, signficantly reduces the temptation to do dangerous and crufty things like trying to have one and the same subroutine handle both OO and non-OO calling conventions.

Makeshifts last the longest.