If one would go to a site like Verizon and do a search for "ruggedized", one could find phones that are a tad tougher than the norm such as the Verizon Wireless G'zOne Boulder or the Motorola Adventure™ V750 (both built to Mil Spec).

Those may be tough, hard-to-break phones, but since the primary attribute is reception, the bigger question re a "survival" cell phone is one of the network itself. My non-ruggedized Nokia and Moto have both taken some pretty bad drops onto concrete and kept right on working.