Google Image Search joins Google’s web search and Google Video in offering suggestions to auto-complete your search, often with a “wallpaper,” “logo,” or other popular terms. Don’t like the clutter? You can turn it off.
Just as with Google Preferences page while signed in, head down to the "Query Suggestions" section and choose "Do not provide query suggestions in the search box." Or, as Google Operating System points out, you can manually add &complete=0 to your search URL if you're not logged in or just want a one-time clean search.
Do you find search suggestions by Google, other web sites, and your own browsers to be a helpful, idea-generating feature? Or, perhaps, are popular suggestions not all that helpful in your search routine? Give us your Google feedback by proxy in the comments.