A simple way of SELECTing values from a comma-separated string

See my later blog post "An updated and better method for selecting values from a string using the APEX_STRING package" for an updated and better way of doing this 

Want a quick and easy way to select from a comma-separated list? Just use xmltable. 

This can be used for a FOR loop too! 

Note: You probably shouldn't use this in an environment that requires high-performance though.  As Mathias Rogel and Carsten Czarski have pointed out here, it's not as efficient as a PL/SQL-pipelined function or a pure SQL-approach - but it does have the merit of being simple.