Open calendar systems, seem to me to be a massively underexploited gap in the Web 2.0 marketplace.
I have yet to find anything that is remotely good enough, and that fully exploits the opportunities that shared time presents.
Sharing time based information creates numerous opportunities and an open calendar with an intuitive UI represents an incredibly useful tool (google calendar doesn’t even do basic stuff like let you mark entire blocks of days with drag and drop).
What would a good open calendar enable?
Sharing of events you are attending with freinds (whilst facebook does this already it only does so for events on facebook, also there is no calendar format (which is frickin ridiculous).
Alerting you of relevant events in area you are in, or are going to be in (info relevant to your future time and space).
Time based contact management – Manage who can contact you and when, create black out zones so you can get work done, coordinate with devices.
Communication syncing – see when best to organise a chat or a meet up without constantly firing off multiple date/time scenarios
Time sharing – prearrange times to spend time with people, before you even know what you’ll be doing. These spaces could be open to suggestions (ie. people could pitch for ways you could spend that time (within predetermined budgets), the lazy way to organise a holiday or meetup).
Flexible work and volunteering management. By showing what you have free and when you can make your self available for work as a freelancer, or for volunteering within the community.
These are just a few things that I would envisage as benefits from sharing time information within a simple open system, I believe as an open source format it would represent numerous opportunities. With respect to a user interface, i’m personally inspired by the idea of an annual calender as a circle (taking influence from Eastern calendars) which would make it easy to drag repeat events such as birthdays into future years.
Thoughts greatfully recieved.
Thanks to James Methley at Technophobia for encouraging me to write this out