Recently I was working on a task of converting the SharePoint site running in ASP.NET 2.0 to ASP.NET 3.5. If you are doing the same there is an easier and nice way to do the same. Please follow this link which guides you a kind of automated way to achieve it. Make sure that you include the System.Web.Extensions assembly in the SafeControls.
Also after done with the conversion I tried to code come web Services by using Hand much without intelli-sence help of Visual Studio, when which I encountered an interesting issue in fact a compiler error which says ‘System.Data.DataRowCollection’ does not contain a definition for ‘Cast’ and the best extension method overload ‘System.Data.EnumerableRowCollectionExtensions.Cast<TResult>(System.Data.EnumerableRowCollection)’ has some invalid arguments. Initially I narrowed down it to be some configuration issue, but it was because of missing Namespace. System.Linq By the fact that all the extension methods are defined in the System.Linq Namespace.
