Last I looked into it, phones that are built for the 'encrypted voice' niche market cost several thousand dollars per unit (a quick google search shows this one which is selling for $3,000: NOKIA E71 ENCRYPTED) and they usually only work if you use them with someone else who has the same phone. Android phones are imo the clear winners when it comes to secured communications with cell phones, they have apps that encrypt text voice and instant messages (and the entire phones storage), and they are compatible with any other Android phone, and they cost a fraction of what a purpose specific encrypted phone costs (not to mention the encryption apps are free).