From this quote, "Just save the images in memory and retrieve them from memory instead of the network when you need to."
If I create a Thread that has a Runnable in which downloads images and stores the image data in memory (variables within an Object), how can I reference the same Object from a different Thread to get the image data in memory?
I'm not sure this is the best way to do it, but when you create your Runnable to go a gradually load images from the network, you can pass it an empty Map (or something similar). The class that's kicking off your runnable should keep a reference to the Map, and make it available to whatever other threads might want to get images.
Then, you can use the String path to the image as the key to see if an image is loaded into your Map cache before you try to go get it on the network independently.