Using two "PDAs" on a daily basis.
1. PalmOne Tungsten T3: My favorite device for reading e-books, playing games and listening to MP3s (in exactly that order).
2.
Nokia 9300: Nokia's "small" communicator. Smaller than the Nokia 9500, yet with all the good features like integrated cell phone and full keyboard, I use it for doing my business and private calls, for contact management, and as a datebook planer.
I don't use the contact and datebook features of the Tungsten at all, because for me there is no reason to carry these information on two separate devices. I figured that I have my cell phone more often with me than my Palm, which I use mainly for reading ebooks.