What is the Camera type used in the mobile phones, looks very small and has good resolution (2.0 MP). I search in the market for the same, but I could not find it.
Sparkfun.com has several cameras that may be what you are looking for. Be warned that they are often difficult to interface with. Check the sparkfun forum for more info on individual camera.
Most cell phones use CMOS imagers. There a numerous interfaces. Lower resolution cameras usually feed directly into main phone processor to do the ISP function. Higher resolution cameras (>3Mpix) usually have ISP in camera module.
ISP (Image Signal Processor) function is the process of generating RGB/YUV pixels from the imager (there are twice as many green image cells then red and blue image cells). It also does white balancing that sets gain levels based on image brightness.
There are some camera modules that have JPEG compression in addition to ISP function. Another recent addition is auto focusing (versus old fixed focus). This uses a voice coil lens driver to focus image.
Unless you have the full specification of the given module it is practically impossible to interface to it.