Hi Robert,
You could add the Other1 field to the grid, but since this field is a text type, it would not be a dropdown. If you wanted to use a dropdown, then you would have to add a new dropdown field to the SalesOrderLine table.
Next, you would make a copy of the sales order screen (QuickBooks_SalesOrder) so that you can edit it, if you haven't done so already.
Then, click the edit button on the SalesOrderLine grid. Skip to step 2 on the wizard to add the new column to the grid. Select the Other1 field (or new dropdown field), set its properties and click Insert Column. Once you save & publish the screen, you will be able to see the field on the grid.
For more information, please see http://www.methodintegration.com/method/kb.aspx?folder=methodcrm&article=Grid&id=94.
If you have any further questions please let me know.
-Russell