1. Budget?
15-17K can extent a bit more if worth it
2. Display type and size?
LCD, size ->3.5 - 4.0 inch preferably FWVGA (854×480)
3. Form Factor? bar, slider, flip?
bar
4. Preferred choice of brand?
Sony, Samsung, HTC
5. Preferred input method (QWERTY, touchscreen, numpad, touch-n-type)...