REVERSE IMAGE SEARCH

hey /b/. i'd like to know what you think is the best way to track down an image that has been used elsewhere online, using a reverse image search or another tool.

all of the following can be accessed using ImgOps (pic related)

google · bing · tineye · reddit · yandex · baidu

are they any others, or more "underground" tools that are also effective?
what has been your experience with using tools like these?

i'd recommend checking out http://imgops.com/, which has a bunch of tools that you can use to search for, edit, modify, and check over images.