Apparently, LJ publishes a list of recently used images on LiveJournal. Most people in that thread are fine with it, but I'm not sure I am.
So I'm going to do a test. This post is public. I'm displaying a photo of a tree that I took not long ago below. It's not too large - only 52KB. I will measure how much bandwidth is taken up by it and how many requests I get for it.
Here you go. Enjoy!