DevExpress announced today the availability of their new data grid control for Silverlight. They are providing it to the Silverlight developer community free of charge. Yes, it is free!! They also provide its full source code.
If you never heard about DevExpress, they develop Windows Forms and ASP.NET components, plus IDE productivity tools (CodeRush and Refactor!). I used their ASP.NET components, especially the ASPxGridView which provides superior functionality than the standard ASP.NET GridView. Now they are releasing their first Silverlight control, but providing it for free.
See the link below for more information about this free control, including registration and download. Also, check out the online demo and the video tutorials: