Big smartphones have proven to be quite popular but few companies have dared challenge Samsung's Galaxy Note, until now. Meet Sony's Xperia Z Ultra, a surprisingly thin yet expansive 6.4-inch Triluminos display.Under the very hood is a 2.2 GHz quad core processor, 2 GB of RAM, 16 GB of storage (expandable of course). Just like the Xperia Z tablet, it is IP58 certified (dust and water proof), so it is dunkable in water up to 1 meter for 30 minutes. Is there a market for this large smartphone which isn't much smaller than many 7-inch tablets? Probably, but we wont know for sure until the Xperia Z Ultra comes to market. Note that from the advertisement, the Xperia Z Ultra seems to be marketed towards ladies which seems spot on since the Galaxy Note seems to particularly appeal to females.