Large APS-C (23.6 x 15.8 mm) sensor Large sensor in Nikon D5000 ensures a good low light image quality compared to smaller sensor, and it also provide shallow depth of field and a nice blurry background when needed.
Large Body Even the smallest lens attached to this body will be a burden to carry everywhere with you.
590g Carrying this weight all day may not be very comfortable for you.
Body Thickness 80mm With a thickness of 80mm,Nikon D5000 is not a pocketable camera for sure.