PDAs and smartphones may have setup screens that let you key these numbers into fields. Then you just click OK to send the changes over the data connection.

After you set up Simulscribe, whenever you don't answer your mobile within in a specified time or your line is busy or you're unavailable because your phone is turned off or out of range, your calls will go to Simulscribe. As with any voice mail service, you can record a personal greeting. Simulscribe provides a dedicated toll-free number you can call to record greetings, set options and also collect voice messages in the traditional way.

Most Simulscribe account options can be set as well using the company's Web interface - you can log in to your account from anywhere using your userid and password. You could even use this interface to upload a greeting that you record on your computer and save as a WAV or MP3 file.

From the caller's perspective, the experience is pretty much the same as with any voice mail service. The default Simulscribe greeting tells callers their messages will be transcribed, and asks them to speak slowly and clearly. You can add a pre-recorded tagline to this effect to your personal recorded greeting, or record your own version.

After callers leave a message, the transcription software Simulscribe uses, which it licenses from a major speech recognition company and then tweaks to work well for voice mail, automatically translates the message into text, embeds the text in an e-mail and sends it to the address you specified, or as an SMS.

My experience with Simulscribe was frustrating - though not, so far as I can tell, because of any flaw or fault in the service. But it may be a cautionary tale. Here's what happened.

I had two mobile accounts on which I thought I would try Simulscribe: one personal account on which, it turned out, call forwarding was not activated, and a test account from Rogers in Canada for a Palm Treo phone I'm reviewing. When I attempted to change the busy/no-answer/unavailable call forward numbers on the Palm using the procedure Simulscribe provided, the phone told me the call had failed.

When I searched out the Call Forwarding Settings screens on the Palm and attempted to change the numbers over the data connection, I received a "network error" message. I tried several times using both methods, but received the same errors each time.

When I asked Rogers about this, I couldn't get a straight answer. I was told the company does not "support" the Simulscribe service. When I pointed out that it didn't have to support it in any active way, but only had to enable call forwarding on the test account, the company's representatives were evasive.

At the time of writing, I had still not received a clear explanation of exactly what was going on. My assumption is that call forwarding is simply not activated on the test account, and that Rogers didn't want to activate it for reasons that became clear. In the last communication I received, the company's PR agency pointed out - "as an FYI" - that SpinVox, a Simulscribe competitor, had recently announced the upcoming launch of its service on the Rogers network. The penny dropped.

What's a poor reviewer to do? No problem. I would improvise. (PDAStreet doesn't pay me the big bucks for nothing.)

Simulscribe also advertises that it works with Skype, the free-or-cheap Internet phone service, which allows you set a PSTN call-forward number to which it will transfer your Skype calls, so long as you have SkypeOut credits. SkypeOut is the company's for-fee service that lets users call regular phones from their computers. I have SkypeOut credits, so I set up Simulscribe to work on Skype.

This was a good test for Simulscribe, as it turned out. Call quality with Skype is variable. At best, it delivers significantly better quality than most cell phone calls, but on the day I was testing, Skype connections were no better than a typical mobile connection, possibly worse, with wobbly-sounding audio. I used a USB phone attached to my computer to make calls to my Skype identity and leave messages with Simulscribe.