Saw this small gem on my LinkedIn Answers network. Someone asked about developing widgets to be used in social networking platforms. Nice answer from Frank Speiser:

This isn't an answer to your specific question, but there's a lot to worry about with compliance for the various social networking platforms out there. Once you build it, you need to maintain it, which is easily more work than actually building it.

You'd do yourself a favor by integrating with Clearspring (www.clearspring.com), RockYou (www.rockyou.com) or Kickapps (www.kickapps.com) to manage the actual bridge to the social networks and community syndication sites. As a plus, these providers may be able to get you placement in widget galleries that you can not get for yourself.