This addon to Firefox works pretty well. It allows you to quickly search for any image on the internet on one of 5 image search engines.
Very simple, and much faster than entering the image URL or uploading the image to the search engine, yourself.
Once you have the addon installed, and you are using firefox as your browser, you simply right click on any image on webpage you want to search, select 'who stole my pictures' from the pop up box, then the specific image search engine you want to use in the next box.
The screenshot shows both boxes open.
The search results will open on a new page, and may include other dating or social site profiles the pic is used on, blogs, any place the picture has been used on the 'net that the particular search engine has indexed. You can use multiple search engines for the same picture, but you'll have to repeat the 'right click' process.
For our purposes, Google, Tineye, and Baidu are working well, and worth checking pictures through. Baidu is doing a pretty good job on 'Asian' pictures. You may want to have one of the various translation addons for firefox installed, that way, you can translate any page that pops up, other than english.
It's easy to use, and really a lot of fun, and an eye opener, to work your way through a couple of pages of profiles or a page of picture thumbnails at a big dating site.
Just as an example, last night I worked my way through maybe 50 'chinese' ladies at Findloveasia, and found 1/3 of the pics to be stolen and of asian models or actresses.