Google calendar is one item from their productivity suite which includes mail, docs and sites and is available to Google Apps and standard Google accounts. All of these applications focus on the cloud computing lifestyle allowing you to login from anywhere and have access to all of your data.
Cloud computing does allow one to access your data anywhere but there are often times when you'll want to use another front-end other than a browser. It could be due to extra support offered by the package, poor web-access etc. Or maybe you just want to have access to your data offline while flying.
The Google Android G1 phone does just this and syncs perfectly with their corresponding cloud services. If you have another device then:
- iPhone/iPod Touch/iCal
- Google Calendar Sync compatible with Outlook 2003/2007
- Google Sync for Blackberry seamlessly integrated into BlackBerry's built-in calendar with two-way over the air sync
- gCalSync for Nokia S60 devices
It seems to be a general limitation to have read-only access to your calendar on the iPhone/iPod Touch when access via CalDAV but I cannot understand why. Apple's own iCal client has full access to this so am guessing that it should be technically possible to get it to work. Apple do seem interested in working with Google and nothing points to this more than the support in Address Book to sync your contacts to Google Mail1.
Google really shines here and due to their muscle are able to offer SMS/text notifications (for free2) and emails when appointments are due.
Depending on the access rights which you set for the calendar others have access either from with Google Calendar or via XML, HTML or CalDAV. This does mean that you're easily able to parse the XML feed for integration into any project you can dream of.