Hori will be releasing their "Liquid Crystal Monitor 4" for the Playstation 4 which will be priced for 32,184 yen (approximately $314). Essentially it is like having a somewhat portable system on the go (you will still need to plug into a socket though). The monitor's max resolution is 1080p.
You simply attach the monitor onto the Playstation 4 and connect the HDMI cable to the screen then finally plug in the power supply to the wall. When you're done using it you simply fold it over like if it was a laptop screen (I wouldn't put it on my lap though if I were you).
No word of a release outside Japan as of yet.
Monitor Specs:
Size: 11 inches wide
External measurements: 279mm x 275; 8mm x 28mm (10.9in x 10.8in; .3 in x 1.1in)
Weight: 1.2 kg (2.6 lbs)
Full screen resolution: 1920x3 (RGB) x 1080
Display color: 18 bit color (262,144 colors)
Maximum brightness: 350cd/m2
Response time: 25ms TYP
Video input: HDMI x 2
Audio output: internal stereo speakers, 2 headphone jacks
Resolution: 480p, 720p, 1080i, 1080p
Power source: attached AC adaptor DC 12V/2A
Electricity usage: 24W maximum
Other: 250 mm (~10 in) HDMI cable
[Translated By Timothy Roy]