My buddy Big Al Harrington has finished his two-part write-up on the End of the PDA for Time Management.
The gist of it, worth reading in its entirety, is that he has found it best to combine the use of paper and a PDA for effective time management. He uses the PDA for appointments and contacts (as I do with my T-Mobile Dash) and the “Hipster PDA” for task management. He, like me, uses a mixture of PDA and paper for notes and reference material. Al uses the Hipster PDA to implement David Allen’s GTD system.
After reading Al’s article and leaving a comment for him, come back and give us your thoughts on it!

I tried to leave the Pocket PC & went briefly back to a paper Daytimer. I Ebay’d my Dell Axim only to purchase another identical Axim a month later. I don’t think I’ll ever go back to paper. Once I have reminders & To Do Lists (in List Pro) that force me to dismiss them, I rely too heavily on them now. For the time being, I will resort to carrying my Axim & my Blackberry for email / phone needs.