Why do we still perform conceptually similar activities--text messaging (SMS), instant messaging (IM), and microblogging (Twitter)--via different applications, separate services, and multiple networks? It's an artifact of history, not design. Sure, we've made progress. You no longer need to install a separate IM client for each service, and Twitter has been baked into many PC and mobile applications. But sending a quick message is still nothing like the frictionless ubiquity of email, where it doesn't matter what client or network you use as long as you have the right address (and don't get dumped into a spam folder, but that's a separate discussion).

SMS provides a sort of quasi-universal service for phone users, but once people pick up a PC or tablet and leave the cozy confines of the telco networks, they've been out of luck, until now. As it's done so many times before, Apple is breaking down entrenched business models in a bid to unify messaging ecosystems with its iMessage service.

Now, Apple has long had a Mac IM client that supports common services like AIM, Google, ICQ, Yahoo, and its own MobileMe. Along comes the iPhone, which of course did SMS but not (at least natively) IM; even with add-on apps, the two worlds remained disconnected. With last fall's iOS 5 release, the iPhone finally got its own native IM client, dubbed "iMessage" in Apple's literature, "Messages" on the phone. Whatever you call it, the client is a swipe at carriers, since iMessage transparently merges the SMS and IM worlds. Send a message to a contact who also has an iPhone, and it's delivered over the IP network using iMessage. Better still, unlike SMS, messages are encrypted (see this review for details). Send to someone on another device, and it arrives as a traditional SMS message. The translation occurs entirely behind the scenes. To both sender and receiver, the message looks the same, regardless of the transport method.

Given the vastness of the iPhone-toting population, rapidly approaching 200 million, the odds that a message will bypass the outrageously overpriced SMS network increase by the day. But what about desktop users?

That's where the next generation of OS X, Mountain Lion, points to a unified messaging future. Apple just released a beta version of one component, the Messages application that replaces iChat in Mountain Lion, and it effectively merges the multiprotocol IM support long a part of iChat with the iMessage mobile service. Since iMessage also support photos, videos, other attachments, and FaceTime video calling--all part of the base OS in a single application--it's looking a lot like a UC alternative. What's more, thanks to the iCloud back-end data synchronization service, messages get pushed to every iOS/Mac device in the recipient's arsenal: phone, tablet, PC, even iPod Touch. Indeed, a UC-like cross-platform notification system. Better still, you can start a conversation on one device, say your laptop at work, and pick it up on another, such as your iPhone in the cab on your way to the airport.

Unfortunately, like that other enterprise messaging favorite, BlackBerry Messenger, iMessage is confined to a single vendor's ecosystem. Yes, unlike RIM's fading product line, the iMessage universe will soon consist of more than half a billion devices. But most enterprise IT teams support multiple operating systems, including Android, BlackBerry, and Windows in addition to iOS. Don't hold your breath waiting for Apple to marginalize a differentiating feature by porting to its competitors, but since iMessage is based on XMPP, it doesn't seem unreasonable that, much like third-party cross-platform clients did with the various text messaging protocols, someone could reverse-engineer iMessage and mimic its features.

Admittedly, Google Talk provides similar mobile/desktop integration and indeed works across platforms; however, it's cumbersome to use (on the PC side, you typically access it from within the Gmail Web app) and not as transparently integrated into Android phones as iMessage is on Apple devices.

Why should IT care about SMS, anyway? Because your employees and future hires use phones to text, not talk. A 2010 survey found the average teen sending or receiving more than 3,300 texts a month--and as any parent of a teenager will you, the trend's still on the upswing. Avaya cites a Pew survey showing that 31% of adults would choose a text message vs. voice communication on their mobile phones. Our most recent InformationWeek Application Mobilization Survey found almost 90% of 693 respondents had deployed instant messaging to their mobile users, while our 2012 Unified Communications Survey found that more than two-thirds of respondents have deployed IM or chat clients to some or all of their desktop users.

And it's not just for idle chatter. That same UC survey found 59% of IM users spent more than three hours per week in the messaging environment. Of course, among other promises, enterprise UC systems were intended to bridge this chasm between mobile and desktop messaging, but even after years of hype, only 36% of respondents have deployed UC. One possible factor: The rapidly changing smartphone environment, dominated by consumer-oriented iPhone and Android devices. It's unclear how well, or even if, stodgy UC systems can deal with these gadgets, meaning it's well worth it for IT to investigate innate messaging capabilities.

Organizations that have already embraced the iPhone should develop an iMessage strategy. Make sure employees have their work email addresses configured as an iMessage recipient address on their phones and that their iPhone numbers are linked to their email addresses in enterprise directories. Mac-friendly organizations should start testing the iMessage desktop client and see how it might be used to bridge the mobile and desktop messaging worlds. Finally, organizations with Macs, iPhones, and iPads should test using FaceTime for peer-to-peer video calling. The iMessage client clearly indicates which contacts have cameras (every recent iPhone, Mac, or iPad), making it easy to see where a quick video call could supplant a text-based exchange.

While Apple is so far leading the way, Google and Microsoft won't be far behind in merging the mobile and desktop/laptop worlds. By opportunistically exploiting features built into base operating systems, many small and midsize enterprises may find they can get all the UC they need.