This is one of those missing features that really makes you ask "what are they thinking" -- complex business systems that allow for on the fly customizations (something that is very common today) need to be able to be handled in Silverlight.

So if you are running into this and not sure how to proceed, here are some links that you might find useful

http://silverlight.net/forums/t/16733.aspx
http://silverlight.net/forums/t/63057.aspx
http://silverlight.net/forums/t/11570.aspx

http://silverlight.codeplex.com/WorkItem/View.aspx?WorkItemId=2810

Free Government Information (FGI) is a place for initiating dialogue and building consensus among the various players (libraries, government agencies, non-profit organizations, researchers, journalists, etc.) who have a stake in the preservation of and perpetual free access to government information. FGI promotes free government information through collaboration, education, advocacy and research

The purpose of Data.gov is to increase public access to high value, machine readable datasets generated by the Executive Branch of the Federal Government. Although the initial launch of Data.gov provides a limited portion of the rich variety of Federal datasets presently available, we invite you to actively participate in shaping the future of Data.gov by suggesting additional datasets and site enhancements to provide seamless access and use of your Federal data. Visit today with us, but come back often. With your help, Data.gov will continue to grow and change in the weeks, months, and years ahead

Businessweek published a rather interesting article that talks about oniline friendships, the data behind them, and how companies are looking to use it.

http://www.businessweek.com/magazine/content/09_22/b4133032573293_page_3.htm

Check out this article on how to add a item to a list in SharePoint via code 

Then you will find this article full of some great resources and examples

http://www.84bytes.com/2008/10/22/advanced-data-visualization-tools-built-with-javascript/