There are times when a new product or service arrives completely out of the blue. That kind of innovation, often called radical innovation, is what most people think of when they think of new product development.

But there's another kind of innovation that's important as well: incremental or detail innovation. That's the process of taking something familiar and adapting or modifying it in a way that is new — and ultimately innovative. Incremental innovation can be recurring, such as the introduction of this year's new car models, or it can be onetime, which is all the rage these days in consumer products.

For instance, consider the screw-off paint can lid (no more spilling or opening with a screw driver) or yogurt-in-a-squeeze-pouch (yogurt on the go, no spoon required). These aren't completely new ideas, but rather “Why didn't I think of that?” improvements or reimaginings that improve already popular items.

So what started me thinking in this MBA-speak? A series of recent developments has focused on reimagining that most basic and long-standing of communications products: e-mail. When you think about it, e-mail hasn't really changed in years. Open. Reply. Forward. Reply to all. File to a folder. Sure, things like spam and phishing filters are new, but they are more about addressing new problems than improving a long-languishing product.

So it was interesting to watch as e-mail providers, ranging from service providers to Internet start-ups, took pains in recent weeks to add some pizzazz, not to mention crucial usability improvements, to plain old e-mail.

Verizon updated its Web-based e-mail service with a new AJAX interface. (Read more on page 16.) Yahoo spent $350 million on Zimbra, an open source e-mail vendor with a focus on adding collaboration to enterprise messaging. Silicon Valley start-up Xobni (“inbox” backward) won the best product award at the Web 2.0 conference TechCrunch 40 by introducing social networking features to, of all things, Microsoft Outlook. The Mozilla Foundation, caretaker of the Firefox browser source code, invested $3 million in MailCo, a project to jump-start e-mail product innovation.

What will come of all these efforts? Who knows? But e-mail feels like a product that would benefit from some incremental innovation.

Certainly the same can be said of the telecom world's most fundamental service: voice calling. Improvements in voice call routing, delivery, identification, storage, integration, unification, convenience, convergence and more are all on the planning board — if not already available today.

Do service providers need to think outside the box to deliver new services? At times, sure. But there's also lot of innovation — incremental but still revolutionary — that can be had by taking today's existing products and — with a slight, inspired twist — morphing them into tomorrow's big breakthroughs.