http://www.washingtontimes.com/news/...is-blackberry/
OK so maybe not the best, but definitely the most secure.
"The top-secret BlackBerry 8830 is in the final stages of development by the National Security Agency, which will soon begin checking to make sure its encryption software meets federal standards. The device could be ready for use in the next few months.
Once in hand, the president will be able to send text and email and make phone calls to others with the secure software loaded on their devices. Others expected to get secure BlackBerrys likely include top aides as well as first lady Michelle Obama. "
It would be pretty sweet to know that, whilst anti-American nerds everywhere were trying to hack your PDA, you had the full support of the NSA behind every text and phonecall you made. But this raises the question: does the iPhone not have that "presidential" image?