How big is too big? The Dell Streak has a new competitor in the race for the largest Android “phone”. A new leak reveals that Sony Ericsson is testing an Android prototype that features a 5.5 inch display and slide-out QWERTY keyboard. The device is said to currently be running Android 2.1 and it could be launching as soon as this fall.

Personally, I think this device is a little too large for my taste. The Dell Streak was already pushing the limits and I doubt this Sony device would even fit in my pocket. And if it won’t fit comfortably in my pocket, then why even carry it around? If I need a bag to lug around another device then I might as well get a netbook with full size keyboard and display rather than attempt to work on this cramp device.

Do we have any takers out there? How would you use this device if it somehow launched in the United States?