The Motorola i530 is a rugged cellular telephone with PTT capability for the Nextel network.  It operates on the IDEN800 band which limits is roaming coverage when measured against other networks, particularly those utilizing GSM.  Nevertheless, I consider it to be a good choice primarily because of it's durability.  This device features a rubberized exterior which is ideal for harsh conditions; it will certainly not be an executive's choice but, on the other hand, a great communications tool for those who work outdoors or in an occupation which makes the device prone to shock/impact.  I found the monochrome screen easy to read both in sunlight and darkness, it is actually easier to read in excessive light when compared to color screens.  Although it does not feature high-end functions such as bluetooth/mp3 player/camera, I consider it a good tool for those looking for a no frills mobile telephone with PTT capability.  According to the manufacturer, this device adheres to Military 810F specifications.