When we have a Grid with Resizable Columns we may need some of them to be non-resizable (ex. a column containing only status icons).
There are work around and customizations:

Column Resize - Min Width on Resize
http://www.telerik.com/forums/column-resize---min-width-on-resize

but I believe it will be more handy to define requested behavior as a property of the specific column (ex. in row template).

Also, for non resizable columns the user should not even take a resize handle when going on a non resizable column boundary instead of try to resize and when the user leaves the resize handle the column is bouncing back (restoring) the minimum width defined.

Regards,

Thomas