Both devices look great just like most Sony Ericsson devices. Not much known about the devices but here are the brief specifications and photos:

   
 G502 Specifications:

Candybar form factor
2100 MHz HSDPA with triband 900/1800/1900 MHz GSM/EDGE
109.0 x 46.0 x 13.5 mm, 83.5 grams
2 megapixel camera
240 x 320 resolution with 262k colors
   

Z780 Specifications:

Clamshell form factor
Quad band GSM/EDGE and triband 850/1900/2100 MHz HSDPA and AGPS
128 x 160 resolution screen with 262K colors
96 grams, 95.0 x 48.0 x 17.0 mm
2 megapixel camera

Via : Into Mobile