In each zone where eggs spawn there is a set number of spawn locations and it apears only a set number of eggs show up at any one point.
We created a group of 15 guys and each took a different egg spawn location and clicked it as they respawned. We found that the quicker the eggs were taken from each area the quicker new ones spawned in the old ones.
Put simply. Get 15 -20 people working together, each takes 1 egg spawn and camps it. we were getting aprox one egg per person every 15-20 seconds.
Enjoy.