You will need to install a user script manager extension to install this script.
Outdated: Sadly, this version is no longer compatible with how Google is presenting its results these days. If it still works for you, count yourself lucky.
If it doesn't, check out the work-around script here.
Replace links and click actions of the Google Image Search results with direct links to the picture, and the page link, very simple version.
As requested by 613 The Evil
Due to the mysterious ways in which Google works, we don't always get the direct links right away, but rather a href="#" at first.
This is why it might take a while for the script to "work".
For this reason, I added a little warning: An exclamation point that appears when hovering over an image that isn't ready yet, with a tooltip (title) text explaining the situation.