What effect are you looking for? delay() stops the program for the duration specified (in milliseconds). If you want a 5 second delay use delay(5000);. Are you trying to do some other processing during the delay?

I was trying to set up a timelapse photography project with Processing (before I found out my webcam already does this).

http://processing.org/reference/second_.html

I used second and just put the current value into a variable marker and waited until second() = (marker+5)%60;

Do you want the feed to go into some kind of buffer and play later though? That might be tricky. It's easy with single frames (just copy() on to a PImage), a live delay would imply some kind of video buffer.