Here is an update (revision 2) of the Interactive Grid Cookbook. You can download it here. This revision adds an example of reordering rows. This has been asked for on the APEX discussion forums. The example is a task list editing page.
The example also shows a workaround for the “no data found” error that can happen when saving data if the SQL statement has a where clause. When the IG SQL statement has its own where clause, such as “... where EXAMPLE_COL = :P1_CURRENT“, if the column is editable and the user changes the value so it no longer matches the where expression you get the error. The reason is that as part of saving the data the IG Automatic Row Processing (DML) process tries to get the latest values for edited records and if a record is now out side of the result set because of the where clause you get the error. A number of people have run into this problem.
Feel free to discus the techniques shown in this app or issue with this app on the APEX Discussion Forum. This is not an officially supported sample but I’ll reply if possible and you can all help each other as well.