Rated 4 out of 5 stars
I tried this out, but like others have said a few of the sites don't work. Still not bad though. The only thing I wish you could do is narrow down the search while right-clicking, rather than just doing a generic reverse image search. The reason being, I mainly have wanted to reverse search for images on Pinterest, to see if anyone had used the ones I'd posted elsewhere.
I wrote a Chrome extension for my own personal use (not publicly posted), but I figured it might be helpful to others, so I also created this quick site which does a similar reverse Google image search, specific to a few popular image-bookmarking sites:
Hope you find it useful.