I would also agree with someone else's statement that it is the spectator's responsiblity to spot the runner. However if your runer has a good idea where you can be found, then generally between the two of you, you'll spot each other. It is also helpful if neither the runner nor the race dress like all the others- ie there are way too many runners with white singlets and black shorts- might consider opting for something unqiue and brightly colored. As a spector, you might consider a big sign, balloons, etc- something that can be easily seen from a distance.