Agile is to Development as Atkins is to Dieting
How's that for an analogy?
But I think there's a bit of truth to it.
Dr. Atkins defined a low-carb diet that many people have considerable success with. The diet involves a small set of restrictions that, when followed, help you lose weight.
In my opinion, however, what makes Atkins successful isn't the specific food choices that it requires, but rather, the fact that it forces you to consider what you're eating. The real benefit isn't the advertised benefit - that reducing carbs will reduce cravings - but rather simply that you need to think about every meal.
Agile development is the same way.
It's not the metholodogy you use that's the magic; it's that you're using a methodology, and one that requires that you talk about it.
Every flavour of agile evelopment, be it Scrum or Pair Programming or XP or insert your favourite here, has some things in common. Frequent communication is the biggest one. Constantly looking at the work you have to do, looking at your progress, thinking about it, and talking to other people on your team and other stakeholders about it.
In the end, that's what matters - not the length of your iterations or whether you call it a Sprint, an Iteration or a Drive.