Here is a link to the newer version of the code library project: http://www.telerik.com/support/code-library/excel-look-and-feel-for-radgrid.
You may also want to take a look at the Batch Edit mode of the grid: http://demos.telerik.com/aspnet-ajax/grid/examples/data-editing/batch-editing/defaultcs.aspx.
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items