I was in Milan when a guy told me Italian men carried three mobiles. One for work, one for the wife and kids, and one for his lover. Keeping worlds apart by giving them different phones to call.

GrandCentral says with enough control, you could keep them separate, and treat them differently, by using one number not tied to any device or service provider. And with their very slick software.

I shot this demo at GrandCentral's Fremont, California, headquarters earlier this month. It stars Craig Walker (CEO in the dark blue shirt) and Vincent Paquet (COO in the pale blue shirt). 2.5 minutes.

In the video:

1. Craig calls Vincent's GrandCentral phone number.
2. Several of Vincent's phones ring.
3. Vincent picks the desk phone and puts the call on speaker.
4. Vincent listens to Craig leaving a voice mail. (You'll hear some echo and latency because you're hearing Craig speak in the room and his voice through the speakerphone at the same time.)
5. Vincent decides to take the call.
6. Vincent presses a key code and joins Craig in the important call. If Vincent didn't take the call, Craig would have continued leaving his voice mail message.
7. Craig explains whey sometimes he wants to take calls from Mrs. Walker and sometimes he doesn't.

From a user view:

• GrandCentral restores call screening, a feature we haven't had since answering machines.
• It shows a call to one GrandCentral number rings on all of your phones.
• Call screening controls incoming calls, the better to manage your time, your privacy and your relationships.

Other notes:

• GC numbers are free.
• GC works from any phone, nothing to download.
• The magic engine behind this lets you do things like transfer a call from one phone (like my Cingular mobile running out of battery power) to another (like my charged Verizon mobile) in mid-call.
• Like Iotum, you can define rules for how to handle incoming calls in a web control panel. You tailor caller experiences and routing. You can tailor for a specific person, or have GC apply rules based on groups the caller belongs to (like family), time of day, or even challenge and response.
• GC's web interface to voicemail rocks. Everyone should take note and steal the ideas liberally.
• The magic is courtesy of their proprietary soft switch. Everything else in their business extracts value from having such a scalable, smart switch.