Yes, provided that your HD HERO Original camera is loaded with the latest software update, you will be able to switch between NTSC and PAL recording.  The HD HERO2 camera has this ability out of the box, without doing a software update.  

Whenever you have PAL selected in the settings menu of the camera, the camera will record at the standard PAL frame rates of 25 or 50 fps.  This functionality makes it easier to edit the HD HERO camera HD HERO2 camera videos together with any other videos recorded at PAL 25/50 rates.