Now you can search for images within Google+, which is an excellent resource for my Search Pic of the Day column.
Dave Cohen from Google announced this on Google+ and shared this screen shot. He said you can now "filter your Google+ search results to only show photo posts. Just type in what you're looking for, and select "Photos" from the filter dropdown."
Here is a screen shot:
So I set up some saved searches for keywords like [google] to see what interesting pictures I can find. The issue is, there is porn that comes up, but that is expected, I guess.
So for example, here is a search for photos for [google] on Google+.
Forum discussion at Google+.