You can use a wide variety of data-sources for grid structure generation (the only requirement is that these custom objects implement the ITypedList/IEnumarable/ICustomTypeDescriptor interfaces). The code under the ASPX/C#/VB.NET tabs demonstrates how to:

• useArrayList object for Telerik RadGrid structure generation
• bind the grid to list of custom objects with Nullable properties (.NET 2.0 feature)
• bind the grid to subobjects by the intuitive and simple dot(.) syntax (specified through the DataField property of declaratively bound columns), for example:
  <rad:GridBoundColumn DataField="Inner1.Inner2.TestProp" HeaderText="Inner1.Inner2.TestProp">
• bind the grid to DataReader

Additional info you can find in these online articles:
Binding to ArrayList
Binding to Nullable objects
Binding to SubObjects
Binding to DataReader