Here’s a rare look at an early build of iOS 4 running on a prototype 64GB white iPhone 4. Unlike the normal multitask function, “you can tap on a window to expand it to fill the screen or long-press on it to bring up the familiar ‘x’ button for shutting it down.” Videos after the jump.

This is all accompanied by a new “Search iPhone” dialog at the very top, which sends you into Spotlight search that looks very much the way it currently does (though it seems to no longer be accessible with a left swipe from the first homescreen as on previous versions of iOS).

[via EngadgetTinhte]