Push to talk, introduced to the business world by Nextel, is gaining popularity outside of the sales force. Some may find it a bother to carry on chirp-filled walkie-talkie style dialogues, but this kind of voice instant-messaging, complete with Internet-style group chats, was bound to catch on. (TIME recently took a look at Ready Link and other push-to-talk services.)

The real draw for this phone is video messaging with sound. Previously seen in the U.S. only on the Nokia 3650 from T-Mobile, video may be the next phone phenom. It's easy to start up: just hit the camera button (for convenience, there are actually two), select "Camcorder" and then have a look. Too dim? Push "Option" and activate the video light. If you really care, you can even manually set the brightness or change the white balance from Sunny to Cloudy or Tungsten to Fluorescent. You can record up to 15-seconds thenĘsend completed video by entering an e-mail address. (If you know people with the same video-capable phone, you can send it to them using phone numbers.) Uploading a clip takes less than two minutes, though quick upload by no means guarantees speedy arrival.

In the style department, the VM4500 closely follows its two camera-phone predecessors, with slight design changes. My friend, who we'll call Mr. T, carries the 8100, and he immediately noticed that the camera itself had been relocated to a more sensible location. On the 8100, you have to tilt the screen away from your eyes to get a level shot; the VM4500's camera is angled just right to let you see the screen and shoot.

The new button layout can be a little confusing. One marked "Speaker" activates speakerphone only if a call is underway; otherwise, it's just a shortcut to voice dial. A button on the side of the phone, referred to in the manual as the "Side Call Key," didn't appear to do anything. After some reading, I discovered it's actually pretty powerful: it redials the last number called and patches it through speakerphone while the phone stays closed, but only once you figure out a Morse-code-like series of taps.

Because this phone represents nearly all that Sprint has to offer, it's a real commitment. Don't buy it unless you're ready to add all kinds of next-generation services to your monthly plan.