PennController.PreloadZip( url )
or PennController.PreloadZip( url1 , url2, ... )
Instead of fetching audio and images from a distant URL for every single one of your PennController trials using one, you can choose to store them in ZIP archives that you upload on your server. Use PennController.PreloadZip to tell where to look the ZIP archives up.
See this page for more details.