It appears that the people have spoken, and Google no longer caches images. I have been embroiled in a battle against bandwidth thieves, who would link to various images from my domain.
I routinely make subtle tweeks to my .htacess file to thwart their efforts. Additionally, I typically review my access logs for new unwanted activity.
While reviewing my access log, I noticed that there is a persistent image cache on Googles servers.
For instance I usually find the following:"
http://images.google.ca/imgres?imgurl=http://bkaeg.org/blog/foo.jpg&..." While at first glance, you'd think I'd be happy that I've got Google juice.. However, upon closer inspection it reveals that people are using the very large image cache as a means for hotlinking. Though I don't directly suffer a bandwidth penalty, I'm quite sure Google takes the hit. Moreover, I would imagine that some people would not desire this sort of behavior.
Well, it appears that Google has discontinued or at least suspended the cache all together. You may recall that there used to be links that point to cache of defunct websites. Even the 'images' links on the Google search engine have a far different behavior. The image cacheing has been suspended or at least discontinued for the public. I'll have to tip my hat to all the people who complained about this annoyance, and even give a knod to Google for finally listening.
Now if they'd only do something about the crap splogs coming out of 'blogspot.'
Update: Apparently the caching difference was particular to my machine ;) Wishful thinking indeed.