Wikipedia page on the vCard format, which includes a list of commonly-used private extensions (X-).
#contacts
Apollo
Pretty slick looking integrated, web-based project, task and contacts management system.
Google Contacts Data API
The main page describing Google’s Contacts Data API, including photo management, updating contacts etc.
Picture Finder
Find pictures for people in your Address Book based on their email address.
How Firefox Contacts Auto-Discovery Works
How Firefox Contacts Auto-Discovery Works
Some cool details on real-world discovery for contact details.
Portable Contacts 1.0 Draft C
“The Portable Contacts specification is designed to make it easier for developers to give their users a secure way to access the address books and friends lists they have built up all over the web.”
KNX.to
Cross-network friend finding service.
CloudContacts
“The CloudContacts service takes your business cards and puts them to use! After we receive the cards, we turn them into contacts you can import into your email application, you can view your contacts online and export the contacts in a variety of formats.”
Idea: Subscribe to vCard/hCard via LDAP gateway
I was talking to Blake the other day about Plaxo, and about how the need it tried to fill (keeping everyone’s contact details up to date) was a valid one, but that it really didn’t live up to that goal. That got me thinking about how a big hole in the distribution of contact details was that you couldn’t “subscribe” to a vCard (contact details) in the same way that you can to an iCal (event/calendar details). Let’s fix that.
I’m imagining an online service (perhaps even just a WordPress plugin?) where you can set up URLs that point to either vCards that are online, or web pages that contain hCards. The system would then periodically (daily?) parse those URLs and load the details into a local cache/database.
The contents of the local cache would be exposed via an LDAP directory, allowing you to connect products such as the Apple Address Book to that directory. Those details would automatically be up-to-date, based on the last time their source URLs were parsed.
This would effectively eliminiate part of the need for services like Plaxo, and would give each person control over their contact information. Ideally the requests could be authenticated so that people sharing their contact details could control their distribution. With DiSo on the way, this would be hot.
Soocial
“Soocial provides a one address book solution to contact management. No matter where you add or change a contact, it will be changed in your other connected devices or web applications.”