Samsung 2233rz is the only 120 Hz on the market at the moment but now it seems that Samsung will soon be joined by Acer GD245HQ. Acer has unveiled details about their first 120 Hz screen that is a 24-inch with a resolution of 1920x1080.
Acer GD245HQ - 120 Hz
Acer presents their new 24-inch GD245HQ (also called G245) monitor with 120 Hz for discerning gamers. It is the first 24-inch screen (23.6" to be exact) with 120 Hz, and larger than Samsung's 22-inch 2233rz.
Thus, Acer GD245HQ is also the first 120 Hz monitor with the 1920x1080 resolution. The high resolution will be appreciated by many gamers that found 1680x1080 on Samsung 2233rz too low.

Acer G245HQ 120 Hz
120 Hz ensures smoother and faster motion reproduction compared to the traditional 60 Hz LCD monitors. 120 Hz should not be confused with the 100 Hz and 200 Hz technologies available on LCD-TVs today. 120 Hz on Acer GD245HQ means that the screen can receive and display 120 frames per second.
Other technical specifications: a response time of 2ms (G2G), dynamic contrast ratio of 80.000:1, brightness of 300 cd/m2, 72% NTSC colour gamut and viewing angles of 170/160 degrees. The monitor features a TN panel.
Acer G245 supports 3D
Acer GD245HQ supports 3D using NVIDIA 3D glasses. The screen is a so-called"3DVision Ready" monitor. With 3D functionality, players can experience a new and improved depth in PC games.

Acer G245HQ 120 Hz
120 Hz is also a prerequisite for 3D images as 3D reproduction requires twice as many frames per second compared to 2D, because it transmits images to both eyes.
New design
Acer GD245HQ has a new design that combines high-gloss black materials with orange. The stand enables users to tilt and swivel the monitor and furthermore G245 has a pivot function.

Acer G245HQ
Acer G245 incorporates both digital DVI and HDMI, as well as analogue D-SUB (VGA) input. The D-SUB port does not support 120 Hz, though.
Launch date: January 2010.
Price: Unknown
More CES 2010 news here.