SE question: if you enable hotlink protection in .htaccess will google
 

spider your images ?

you know - images.google.com

yes they will spider it. Google creates it's own thumb. This is actually a good way to get traffic. If you set up htaccess right, when someone clicks to see the image, they can be pushed off wherever.
Just make sure you use keyword rich names for the images, and keyword rich alt tags.

Yeah, that's what I was doing :)

good advice