If you want to write an application that reads Analytics data then the new Google Analytics Management API should make it much easier.
It provides read-only access to Google Analytics configuration data. It consists of five new Data Feeds that map directly to the Analytics data model.
The previous API had a tendency to overwhelm apps by returning all of the data in a raw unfiltered form. Now you can request data more selectively and hence make apps more efficient and responsive. You can also access multiple accounts at the same time.
Currently the API is part of Google Labs and is only in beta but its good enough for you to start using and get ahead. However Google warns that it is still adding to the API and it would be better to use it only for experimental apps.
Teach Yourself Google Analytics