==
http://www.research.digital.com/wrl/projects/Factoid/index.html
What is a Factoid?
A Factoid can be viewed in many ways. Perhaps the simplest is to think
of it as a minimal PDA. It is about 3" long, 3/4" wide, and 1/4"
thick. It has no display, no buttons, no microphone, and no speaker. The
only I/O device is a 900MHz radio with a range of 30 feet. There is
no power switch, as the Factoid is always turned on. The device fits on
a keyring using not much more space than a key. I expect people to
carry their Factoid around with them in their pocket, daypack, or
briefcase.
The Factoid's purpose in life is to accumulate information that is
broadcast from other Factoids, and upload it to the user's home base.
The
sort of information envisioned are tiny facts, such as one might see on
a sign, in an advertisement, on a business card, or on the display of
an instrument like a thermometer or GPS receiver. These facts are small,
say 200 bytes.
While gathering up data, a Factoid is also on the lookout for an
Internet connected Factoid server. When it finds one (that is, when you
walk
near one), it uploads the facts to the user's home base in a reliable
and secure fashion, and deletes them from its own memory.
Once uploaded, these facts are kept forever. There simply is no need to
delete things that are only 200 bytes in size. If you gathered 1,000
facts per day for a year, that only comes to 73MB per year, and is
highly compressible. Thus, they can be saved forever and constitute a
sort of history of the user's life.
At home base, the user interacts with application software to access his
lifetime collection of facts. Various reports could be generated,
perhaps in the format of a trip diary, a daily diary, or perhaps even
client billing records. Search engines could be used to find that
"needle in
a haystack" fact that you want to recall. Since this lifetime collection
of facts is very personal, privacy concerns are a major part of this
project.