Stocks carrying split-GFP and other split-FP components can be found here.
Split-fluors are being developed for a variety of uses, including 1) assessing the proximity of cellular membranes , 2) GRASP (GFP Reconstitution Across Synaptic Partners) in which non-functional split-GFP proteins expressed on the extracellular membrane of different neurons can reconstitute a functional fluorescent protein in places where the two membranes are in contact and 3) studying protein expression and localization by endogenously tagging a protein with one split component and visualizing only in cells where the two components of the split-FP are co-expressed.