Rated 5 out of 5 stars

Wow this is exactly what I was looking for. I had been using the Googlenlarge greasemonkey script but it hasn't been updated in years and so is broken. This add-on shows large full-size images almost instantly. I'm looking at 4Mpixel+ images. It allows you to go to another thumbnail without first having to move the cursor to a white space like you had to do with Googlenlarge. I love the 'Save Enlarged Image As…' context menu item that saves the original full image. I think the menu item name is somewhat misleading. It implies that it saves an upsampled image instead of the actual original image. I think 'Save Full Size Image As…' would be more intuitive. Wonderful add-on.

This review is for a previous version of the add-on (2.6.1-signed). 

Thanks for the review and for the menu item name change suggestion.

There is actually already a hotkey for Save: while a pop-up is displayed press the "s" key (without any Control or Command key).