Wikiwix search engine now has an image search function. http://www.wikiwix.com/?img=true&action=&lang=en
They wrote a bit about some special features it has on the VP http://commons.wikimedia.org/wiki/Commons:Village_pump#Wikiwix_for_Commons
Give it a try, report if you find anything very useful or very broken. (Best to report on the VP I think)
For my part, I find it much less useful than Mayflower because there's no metadata display, and also it seems to show lots of thumb results to images that don't actually exist.
cheers Brianna