It REALLY depends on what you use each piece of equipment for and what you want (or demand) from your equipment. I commute by train to work, so I like having an ultra-portable, Internet-connected notebook, a PDA for my expenses, maps and non-Net connected entertainment and information and a cell phone for Net access. For me, a TR a Clie NZ and a small phone work the best. (I found out the hard way that I prefer descrete phone/PDA solutions, but I won’t give up my P900 :wink: ) One of my friends uses a 17” Powerbook and a Nokia 3650 for phone/Net/PDA. He prefers OSX and uses the Apple as his main desktop but has no need for any real PDA solution.
You’ll have to weigh your needs yourself for each piece of equipment and the thickness of your wallet. If you aren’t bothered by the relatively simple PDA games around or aren’t a mobile gamer, you don’t have to worry about the PSP. Are there any Palm apps that would work on your Clie or Treo 610 that you would miss terribly on the P900? How many music files do you want to carry with you? In what format? Do you mind looking like an utter fucking nerd with half a dozen pieces of equipment hanging on your body?