CRASH! Rated 2 out of 5 stars
It caused crash on MacOSX and maybe on other systems too.
Here, how to reproduct the crash in a virgin FF with just! this Linkvisitor extension in use:
1. Upload any image on: http://imageshack.us/
2. On the left side in the middle of the page you will see the thumbnail (200x200px) of your image. Click on it.
3. Now, you are on a new page. Right-click on your image.
The Context menu tries to open, but it cannot and crash immerdiately Firefox!
Hope it will get fixed soon.