One of the topics I will discuss at next week's Sustainable Turfgrass Management in Asia 2010 seminar is nozzle selection, spray droplet size, and water volume. Depending on the product (fertilizer? herbicide? fungicide?) being applied, its mode of action, and the reason for the application, one can choose the nozzle type that will produce the most effective spray pattern on the turf.
The Turf Diseases blog has some good posts on this topic, including photos that show the drastic differences in spray patterns between different nozzles and tips on improving disease control by proper nozzle selection.