Heh, the airflow thing is as old as the idea of a gaming computer. Back when computer parts including cases were much more expensive, modding a case for improved airflow could be considered as a serious hobby and ghetto mods were also quite popular. I recall making an air duct for the CPU fan out of a milk carton, worked pretty well! Some guy told that modding cases was far less dangerous than modifying motorcycles which he had done earlier - something that his wife appreciated after several injuries.
As for airflow, the old basic rule still applies: Cool air in from the lower front end, hot air out from the upper rear.