Andem - 2:14 pm on Jun 6, 2012 (gmt 0)
The video where Matt Cutts states that PageRank "flows" through image links: How can PR flow through image links when images can't actually link to anything? If he stated that PageRank flowed TO images, then we would have something conclusive.
Additionally, I have yet to come across an image with Toolbar PR.
Since I link to a lot of higher resolution photos purely for my users, I'm thinking I might start showing links to high resolution photos only if the user has the user agent of one of the major browsers, thus excluding Googlebot.