Flickr made some changes to the search box to let you search everyone's photos, your contacts, and Flickr pages at the same time!
Flickr's search box is now able to search Everyone's Uploads on Flickr by default on all pages.
"After you start typing you can search for photos, or use the new! search menu that pops up to let you quickly navigate to a contact's photostream or to a relevant page on Flickr like Updates from Your Contacts, Your Sets, Flickr Groups, etc.
You can jump to nearly any page on Flickr by typing just the first few letters of its name," explains Flickr.
"After combing through a small mountain of anonymous search logs -- light reading for our engineers -- we noticed that most people on Flickr prefer to include all available images in their searches.
We have added an extra search box on group pages that searches only the group.
When doing a search you can also use "More search types" to instead search Your photostream, the photostream you are viewing, Groups, or Flickr Members."