I ran into an issue where I needed the Checkbox column of my radgrid to look like it was enabled (because it was hard to see the disabled checkboxes), but not act like it was enabled.
The reason I'm posting this here is because I couldn't find any easy solution on the internet or forum searches.
The first thing I did was not use a GridCheckboxColumn, I used a GridTemplateColumn with a checkbox template.
I then put onclick="return false;" in the checkbox attributes so that it doesn't do anything - effectively disabling the checkbox.
Here's the code in case it can help someone else: