Look no further than TinEye.com
Let me tell you what happened to me:
A partner at work gave me some poorly printed out images on a contact sheet (4 images accross, 5 images down, on a single A4 sheet), and asked me get the contact details for the suppliers of the products on the contact sheet. The images had no captions and were printed out on low rez. (72dpi).
WTF! How will I find the supplier certain component with only a poor paper printout of what the product looks like?!
Then I had an idea!
Snap a pic of the printout on my cellphone (i don't have a scanner), and upload it to TinEye. In less than a second it gave me 12 websites that the image appears on (one of them being the supplier, 3 being distributors).
'MAGIC' I tell you!!!The site is sortof a reverse "google images". I love it! If you are into this sorta thing, give it a try.
The site is not perfect. But it's libraries of searched sites grows and last time I looked they added 37 million new images (at least that's what they claim on their twitter feed)
(DISCLAIMER: This is my personal testimonial. I am not paid for saying this, and am in no way affiliated with them, or on their payroll.. but if you guys at Idée Labs/TinEye.com want to gimme some $$$, feel free, lol)