Guys, as we build our system, let's keep these in mind. (Thanks to Dion Hinchcliffe) What a tremendously insightful list of guidelines! Rachel Cunliffe simply calls it "me first". both posts are excellent reading.
Encourage Social Contributions With **Individual Benefit**
Make Content Editable Whenever Possible
Encourage Unintended Uses
Provide Continuous, Interactive User Experiences
Make Your Sure Your Site Offers Its Content as Feeds and/or Web services
Let Users Establish and Build On Their Reputations
Allow Low-Friction Enrichment of Your Information
Give Users the Right To Remix
Reuse Other Services Aggressively
Build Small Pieces, Loosely Joined
I think the key point that Dion is making, which underpins all the rest, is this:
The idea is that most people will not spend the time to contribute content or enrichment to a web site unless they are getting something out of it. With social bookmarking, it's the fact that your bookmarks are uniquely valuable to you personally, regardless of whether they are socially shared.
No matter how great our ideas are, how flexible, how WS integrated, how small, how layered how whatever… the contributor must receive real and immediate value. Only after that can we expect submissions and only then after that can we expect our social software to kick in and begin mashing or enhancing the value of having brought information together.