New York ? In business, communication is key.

Whether it’s staying on top of the latest market alerts via e-mail or getting a quick briefing on a potential client’s likes (and dislikes), those who can get information while on the go are ahead of the game.

So it’s no surprise that Wall Streeters, insurance execs, bond traders and just about anyone else apt to be wearing a suit either has a BlackBerry or wants one.

Now they have one more reason to desire the newest device from Waterloo, Ontario-based Research In Motion (RIM): a built-in phone.

The BlackBerry 5810 features end-to-end wireless e-mail, accessible directly from corporate mail servers and POP3 addresses.

Also present is a wireless Internet browser, Short Message Service capabilities, address book and organizer.

The 5810 also boasts complete compatibility with BlackBerry’s Enterprise Server, meaning companies that already have deployed previous models can support the new model without having to upgrade their software.

It is only underneath the black carapace, measuring 4.6 inch by 3.1 inch by .7 inch, that RIM has forced the BlackBerry evolution.

Instead of using only GSM phone service, the 5810 takes advantage of GSM1900/GPRS networks for its voice and e-mail applications. That means the device is always on, always retrieving e-mail and ready to take phone calls.

And with a variety of third-party applications available, 5810 users can view, print and fax e-mail attachments without having to sync with their personal computer.

The standard browser can access WAP and WML sites, but even with GPRS (Global Packet Radio Service) I found that it took a few seconds to load sites, including offerings from CNN.com and other news sites. Still, a four- or five-second wait didn’t deter from the functionality of catching the latest Braves and Mets scores as I walked the streets of New York.

The other major change is the use of the Java 2 Micro Edition as the basis of the operating system. That gives users the opportunity to take advantage of Java-scripted programs that are prevalent on some existing phones, most notably those used on the Nextel network.

The addition of the cellular phone is perhaps the strongest point of the 5810, but it’s in need of better integration.

Unlike the BlackBerry’s closest competitor, the Handspring Treo, there is no way of talking or listening without using an earbud and microphone that plugs into a 2.5-millimeter jack atop the device.

Getting to the phone requires using the jog shuttle to highlight the phone icon, then punching in a number on the thumb-operated keyboard. It’s a minor quibble, but I’d like to have been able to go into phone mode with just one push of a button. Of course, the 5810 does feature conference calling, call forwarding, caller ID and call waiting.

Unlike the Treo, I could use other BlackBerry functions while talking on the phone. While a friend and I decided where to meet for dinner, I checked my calendar to see if I already had plans (I didn’t).

The 5810 is currently being marketed with GSM/GPRS access on VoiceStream and AT&T Wireless. My model came with the former.

Using the phone was easy, and the quality of the audio, both listening and talking was clear.

That said, the 5810 isn’t an inexpensive proposition. It retails for $499 with activation from VoiceStream and AT&T Wireless, and it does suffer from my long-standing beef of having a monochrome display.

Still, given its relative ease of use and quick learning curve, I may have to get one for myself, so long as I don’t have to wear a suit.