Pipelined functions in Postgres

Hello Lister,
I am curios whether I can emulate the Oracle pipelined functions functionality in PG too (using RETURN NEXT ). For more
information and examples about Oracle pipelined functions see:
http://asktom.oracle.com/pls/ask/f?p=4950:8:8127757633768425921::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:4447489221109

I have used  pipeline functions in DWH enviromnent  with success and would like
To use similar concept in PG too.

Any help, examples , links and  shared experiences would be greately appreciated.

Best Regards.
Milen