I would really appreciate it if it were possible to specify an arbitrary lisp function to process node-properties when creating a column view.  For example, you can currently have something like:

* Top node for columns view
   :PROPERTIES:
   :COLUMNS: %25ITEM %TAGS %PRIORITY %TODO
   :END:

But I'd like to be able to do something like:

   :COLUMNS: %ITEM{fn:process_item} %TAGS %PRIORITY %TODO

which would pass the ITEM property's value as a single argument to the process_item function.  The returned value/string of the function would be what appears in the column view.