I've been using the Ajax Data Controls (ADC) for 9 months. I recently joined their development team to convert the controls to VS 2008/.NET 3.5. It's a really cool control set that uses AJAX for the complete data transaction. The documentation is pretty deep and there are a few good examples. You should check it out by visiting http://dotnetslackers.com/projects/AjaxDataControls/. You can download the source and binary on CodePlex by visiting http://www.codeplex.com/AjaxDataControls.
If you have any suggestions, please pass them on. I'd prefer if they were submitted using the Issue Tracker on CodePlex.