You can use the parallel port for DIO in LabVIEW. There is a KnowledgeBase article on this topic at
http://zone.ni.com/devzone/conceptd.nsf/webmain/72C6FC6CE4AD4D1386256B1800794596?opendocument
As for the best way to synchronize a camera with a digital pulse, I am not sure what "driver" you want to synchronize with. I'd suggest looking through the available example programs for ideas. Are you using IMAQ? If so, search the Technical Resources in the Example Programs category for "+IMAQ +trigger". You should get several hits. http://www.ni.com/support/
