Finally checked to see if someone had already posted something like this and didn't see it. It's an irritant to me (maybe not a rational one) that you have to use >Cols > Add Multiple Columns... dialog to simply add a column in the middle of a table. This script mimics Excel's long-time approach: select a number of columns, click a command to insert that same number of columns adjacent to the selected columns.
I have this script pegged in my Cols menu (via the menu customization tool).
dt=current datatable();
col=dt<<get selected columns;
nc=nitems(col);
dt<<add multiple columns("boo",nc,after(col[nc]),character);