These tiny eggs are attached by a thread to the tips of leaves and thorns on many different plants. They seem to defy gravity - the threads are very rigid and hold the eggs upright. I suspect they are associated with some tiny spider species, which is the only thing that I can think of that is so profuse and so small in the yard. Unfortunately, I have not gotten a photo of the spiders themselves. Any other thoughts?

These eggs are really only about 1 mm - the photo was taken with a macro lens and extension rings to get magnification.