I'm prepping for my talks at Presence 2.0: Rise of the Living Social Network. At CES2008 I was looking for presence-infused objects. Four items bring excellent learning points.

1. Trash Can With Proximity Sensor. Here from the CES Hilton International Exhibit Hall is a wastebasket that opens when someone comes near. This is more sanitary than using your hand and more convenient than using your foot.

A small sensor checks a few times per second for an object to come in its view (in front) and in range (about one foot). When triggered, it tells a motor to open the lid.

Is this presence? No identifying data was shared by the user. The basket doesn't share any information. Could the infrared signal reflected off an approaching person be a passive presence signal? Until now I've considered presence to be intentional. If tacit presence is where you consciously share your data through your behavior, is passive presence when you are unaware and don't opt-in? 

2. The Bed That Senses Snoring. The Starry Night Bed listens for snoring and raises your side of the bed until you stop. There is no reason, of course, why the bed could not log and stream your snoring timeline. This could be valuable to your sleep therapist or to potential bedmates.

The bed doesn't distinguish between which person is snoring, just which side of the bed.

This illuminates an important presence principle: tie data to one entity. Can we have collective presence (somebody in this bed snored) without individual data? Should we?

3. Zoombak GPS Stick. Zoombak is a GPS gadget. It clips on a dog collar. "A lost dog can't talk. But now he can text." A geopresence service. 

The Zoombak locator sends GPS satellite data by SMS text messaging up to Zoombak's servers. An SMS down to the locator can update its software. 

On the Zoombak site, customers define safety zones like home, work, school, etc. Zoombak will alert a dog's owner if it leaves a zone.

Scenario 1: Throw it in your parents' car before your next party to get that "they just left work" warning before they return.

Scenario 2: Exchange Zoombak codes in a trust ceremony with your lover so you always know where each other is.

Scenario 3: Build an app that compares geopresence streams. So you know when your lover and spouse meet.

Scenario 4: Buy a scanner that detects GPS devices on your person or on your property, especially ones you don't control.

Lesson: privacy and access controls make or destroy the value of presence.

4. Conflicting channels of presence data: Skype on PCs and Skype on devices. Your Skype status on PCs is usually tacit, tied to how long you are inactive with mouse and keyboard. You can set how long until you are "away" or "not available" and choose whether being in a call will turn on the "do not disturb" status.

This is apparently not the same for Embedded Skype, the version found in PC-free, stand alone phones like the Belkin on the left, new at CES2008. You can manually set your Skype status but it will stay that way until the device is reset or you manually change it. [Note to Jean: how does this affect the number of simultaneous users online?]

Of course I can have multiple devices connected to the Skype network at the same time, all with my Skype name. At times I have had five devices connected at once (desktop, laptop, Nokia N80, N800, IPEVO Solo). When you Skype me, they all ring.

But which one should be authoritative for my presence? Just because I'm not at my desktop doesn't mean I'm not within reach of my fring- or iSkoot powered mobile phone.

What is the logic for determining my Skype availability?

Where does that logic live?

How fresh and precise does it need to be?

How are conflicts resolved and will consumers of the result understand the result?

Lesson: Good presence architecture creates presence signals others can trust and use.