I just found a quick and easy way to do a hard reset on a Treo 650 -- without sliding open the back cover and then going through the gyration of pressing in the reset pin and holding down the power button while watching the screen from the circular Palm logo to appear.

If you have a security program like Treolock, PDA Defense or mSafe, just type in or send yourself the "bomb" code -- poof, your Treo is wiped. As far as I can tell, this accomplishes the same thing as doing a hard reset.