Hover Zoom - Enlarge thumbnails on mouse over.

Visualping - Visualping is the easiest to use website checker, webpage change monitoring, website change detector and website change alert software of the web. Read more about Visualping.

Imagus - The extension is intended to complement image features that (I think) is missing from Opera by...

Distill Web Monitor - Distill is a web monitoring tool. It can monitor RSS feeds, a webpage or a part of webpage. Alerts in the form of pop-up, audio or emails can be received.

Image Max URL - Help find larger or original versions of images, including a customizable image popup feature

PageProbe - Automatic Page Monitor - Create automatic monitors for detecting and scanning changes on web pages, evaluate content based...