Today we get a video of the unreleased phone BlackBerry Curve 8520,Despite ho-hum specs (EDGE-only, 2 megapixel camera sans flash, 320 x 240 display, Wi-Fi), the BlackBerry 8520 certainly sports a lot of design departures for RIM: more rounded corners, new indicator LED, top-mounted music controls, and of course the trackball replacement.

Calling it "optical" might be a bit of a misnomer, but the bottom line is that it’s a touch-sensitive pad that might turn your usual habits on its head. Apparently the Gemini will be geared for the lower-end, so expect some competitive pricing when it's released. Now,let's see the video:

If you want to know more info,please see the following review of BlackBerry Curve 8520's hottest points:BlackBerry Curve 8520 Optical Trackball,BlackBerry Curve 8520 Media Buttons,BlackBerry Curve 8520 Display and other specifications.

BlackBerry Curve 8520 Optical Trackball - There are a couple of other smartphones on the market that use a similar optical trackpad for navigation, and I'm happy to say that RIM's implementation of it on the Curve 8520 seems to be pretty smooth. You can watch the video above to see it in action. Just like the standard trackball, you can adjust the sensitivity of it under Options > Screen/Keyboard. With the Audible Roll setting on Mute, I was a little tripped out by the lack of noise while navigating. With no tactile/audible response, you're really forced to look at the display to see just how far you've moved. I turned the audible roll onto Click, and from there felt immediately more at home. For navigating the OS and doing things like web browsing, the optical sensor works well. I guess it is an eight-way pad, as I could scroll diagonally while web browsing. And it does "click" down, like a regular trackball, for making selections. So far, the only place where I've found myself having a bit of difficulty with the optical input is playing BrickBreaker. I think the traditional trackball is probably better for quick, accurate motions. Though practice does make perfect. I've heard sweaty fingers and being in bright, bright light can cause issue with this kind of an optical input, but I haven't experienced any issues yet. All in all, so far it's a thumbs up from me. And with no moving parts, it should prove more durable than the traditional trackball. 

BlackBerry Curve 8520 Media Buttons - New to the Curve 8520 are dedicated media player buttons, located at the top of the device. While there's no dedicated lock key on the BlackBerry 8520, holding down the Play/Pause button for two seconds does put the device into standby mode. 

BlackBerry 8520 pics gallery

BlackBerry Curve 8520 Display: The Curve 8520 features a 320 by 240 resolution display. I left all my older BlackBerry devices at home when I came out to Orlando for WES, so unfortunately while writing this don't have an older device to compare to (will follow up next week with direct comparisons). I can say that while the display shows a decent picture and video, it is definitely a step down if you've ever used the Bold, 8900, Storm or 9630. And where you really lose out is in web browsing. 320 pixels just isn't enough these days for those of us who like to browse the web on our smartphones.

BlackBerry Curve 8520 Other Stuff: Be sure to click the images above to zoom in on the photos and get a better look. You'll see the keyboard is much like the 8900's  but with a slightly different bottom row. There are actually two notification lights. The battery door doesn't feature a latch, but is sort of gently pried off.  It is easy insert and remove microSD cards into the media card slot  and you don't need to remove the battery to access it.