Likewise, a second pair of wires goes from the connector at the base of the Visor to the springboard and is used for charging the phone’s batteries (which requires much more power than can be provided over a standard Universal Serial Bus interface). The speaker for the VisorPhone is in the black module itself. (There is also a jack for a headset.)

Because of this advance planning, the Visor and VisorPhone combo is significantly smaller than other ill-fated integration attempts. My pdQ was a big brick that was awkward to carry; worse, the pdQ had two different user interfaces — a keypad for the phone and the LCD screen for the Palm. The new combo, on the other hand, weighs 8.5 ounces and fits in my shirt pocket. Better still, the VisorPhone is completely controlled by a set of PalmOS applications that automatically get installed on the Visor when the module is inserted.

Making phone calls is pretty easy. You start by clicking the “phone” button on top of the phone module, which makes the Visor display an application with 10 auto-dial buttons. Touch a button with the Visor stylus (or your finger) and the phone dials. If the phone number you want to call isn’t in your auto-dialer, you click the “phone” button again and the Visor will display a telephone keypad; you tap the number and then talk. You can also dial any phone number in the Palm’s address book by tapping the number displayed and then confirming that you wish to dial it. Finally, you can dial any number in a memo or on your calendar by selecting the number with the stylus and then pressing the “dial” button.

The Visor displays the call’s elapsed time, and you can put a person on hold by tapping a button on the phone application. You can also place a second call or handle a second incoming call. Or, if you are exceptionally good at multitasking, you can click into another PalmOS application. You can even turn off the Palm, since the phone has its own battery and built-in microcomputer. Just about the only thing you can’t do is pull the VisorPhone out of the Visor’s springboard slot — that makes it hang up.

But voice calls are just the beginning of the action. The second button at the top of the module is for sending and receiving SMS messages. (SMS stands for “short messaging service,” and is built into the GSM the VisorPhone uses.) Sending SMS messages from a conventional phone is quite painful, but doing it from the PalmOS interface is as easy as putting an appointment into your calendar. And because of the gateways between cellphone companies and the Internet, you can use the VisorPhone to send and receive brief e-mail messages. This isn’t as good as with the BlackBerry pagers that are all the rage, but it’s adequate for many purposes.

The VisorPhone can also be used as a digital GSM modem to connect to the Internet. Although this service is expensive — it costs as much as a voice call (plus the $20 per month extra my cellphone company charges) — it lets you access your e-mail, surf the Web and download the latest news with AvantGo.

The VisorPhone’s paging, e-mail and Internet features are available with the OmniSky Minstrel S wireless modem (which costs $299), and the service is $39.95 per month for unlimited use. By contrast, the VisorPhone costs $299 with cellular activation, $499 without. (My GSM provider is VoiceStream, which charges me roughly $59.99 per month for 900 minutes and 900 SMS messages.)

Because the VisorPhone requires GSM, you can only use it with digital service from companies like VoiceStream and Cingular Wireless (but only in the regions that were formerly Pac Bell) — and not with Sprint or AT&T’s cellular service. Handspring decided to build a GSM phone so that it could be used in either the U.S. or overseas with few modifications. Unfortunately, the phone isn’t dual-band or tri-band, which means that if you travel between the U.S. and Europe, you need to get two VisorPhones, one for each market. (AirPrime has announced that it is developing a CDMA module for the Visor, but that phone is not yet available.)

Because the entire PalmOS interface is at your disposal, it’s a lot easier to use a VisorPhone than a conventional cellphone. For instance, you can drag and drop the auto-dial numbers from button to button — and from page to page (the VisorPhone has five pages of auto-dial numbers). There is also an easy-to-use interface for managing the nearly 200 phone numbers you can store on the SIM chip that holds your GSM account information. And since the VisorPhone uses SIM chips, you can switch back and forth between a regular phone and the VisorPhone by swapping the chip from device to device. It’s kind of cool.

The VisorPhone isn’t the perfect blend of a PDA and a cellphone, but it comes pretty close. My biggest complaint with it is the ringer. Instead of having the traditional loud beeper common on other cellphones, the VisorPhone uses the Visor’s built-in speaker, which isn’t loud enough to be heard on a crowded street. What’s worse, the phone application comes with a limited selection of rings, and you can’t create your own tones. This is pretty disappointing, especially when my previous cellphone actually let me choose different rings for different caller-ID numbers — letting me have a different ring for my wife than for the rest of the world. With so many things done right, it is sad that Handspring got the ringer so wrong.

Another problem is battery life. The phone’s battery gives three hours of talk time or two days of standby use; SMS messaging has no noticeable impact on the battery at all. That’s not bad, but my Motorola two-way pager runs nearly five weeks on a single AA battery. Battery life will matter less after Handspring brings out its new charging dock; because of a technical oversight, the charging docks for the Visor Prism don’t charge the VisorPhone.

My final complaint is that the phone doesn’t work unless it is plugged into the Visor. This creates an interesting problem: If you are using your springboard slot for something else, like taking a photograph or playing an MP3 file, there is no way to make or receive calls. I would at least like to be able to receive calls with the VisorPhone (presumably using a headset instead of the Visor’s built-in microphone). That could be accomplished with some kind of firmware upgrade to the current phone.

Overall, I like the phone a lot. It’s not perfect, but if you’re looking to reduce technoclutter and escape from that particular geek style that demands having a different gadget in every pocket, the VisorPhone may be the best thing going.