Japanese manufacturer Toshiba showed off a new range of LCD screens for smartphones that have a pixel density of 367ppi, much higher than the iPhone 5 326ppi and ideal should Apple decide to up the screen size of the iPhone 5 to 4 inches.
At this size, Toshiba is able to deliver HD ready content, something unheard of for such a form factor. Furthermore, it ups the ante by delivering a rather head turning 1500:1 ratio. We did point out that one of the main technological issues that Apple would have to solve before rolling out a bigger screen on the iPhone 5, would be to up the display resolution in order to keep up with the retina display moniker.

Engadget, which reported the story from the SID 2011 event, did not mention power consumption though or whether the screen can be scaled to iPad 2 display size.
Toshiba has not confirmed when the technology will be rolled out, whether it will be offered to third parties (like HTC or Sony Ericsson) or if it would be restricted to Toshiba products only.
Another smaller 3.3-inch screen with a 300ppi and a 480×864 pixel resolution was unveiled at the same event but is highly unlikely to make a big splash, as smartphone manufacturers seem to be focusing on the 3.5-inch and bigger models.
A few days ago, Samsung announced a 2560×1600 pixel display which would be perfect for the iPad 2 as it delivers retina display resolution.
 

Toshiba Unveils 367ppi LCD : Perfect For Hi-Res iPhone 5