Recent reference query: pictures of a saddleback caterpillar, a species of hairy stinging caterpillar. Yes, someone got stung.
As this is a fascinating critter, it seems ideal to use it introduce various image searching tools. In all cases our search string was saddleback caterpillar. Please look through these links. You will see, as well as a lot of caterpillars, differences in the way the search screens are fashioned.
Picsearch Clicking on Advanced Search gives you the opportunity to set limits: image/animation, size and BW/color
Exalead Easy to limit by size, and by a quick click to layout, file type and BW/color. You also can search within your results. Tells you the domain source for each thumbnail right there on the page so you don't need to mouse-over each one.
Google clicking on Advanced Image Search gives you size, BW/color, file type and Boolian limitations.
Ask Note the nice expand/narrow feature on the right. This is very useful if one of your search words is ambiguous.
Altavista Easy to limit to just graphics or photos ... see the check boxes at the top? And right there on your results page are options for size and color. (The source option is not very useful.)
Yahoo Easy to limit by size or BW/color. Gives URL without requiring mouse-over.
Flickr Does not index images available on the web, but instead looks for individual photographs that have been uploaded to the Flickr site.
Note 1: Clusty Images uses Picsearch. If we have forgotten other major image search tools, the omission was inadvertent.
Note 2: Google tends to give the greatest number of results. On this search
The tradeoff for the large quantity of images found in Google is, sometimes, some serious pornography, even while moderate safe search is turned on. (Not seen on this particular saddleback caterpillar search, which is why we picked it. )
On another innocent reference quest, looking at the first 20 images. Obscene images?
google yes, the very first image.