What benefit is there in doing this besides being able to immediately call those in my contact book?

Well for me, I just didn't want to carry around my phone and PDA anymore. The Treo is a decent sized PDA, and a slightly bulky phone, but slim enough for me. Also it has most of the bells and whistles of the latest batch of phones like bluetooth, camera/video camera, mp3 player, movie player (with PDA software), games, internet, and, of course, vibrate mode. Actually with an SD slot and an unlimited capacity to run Palm OS software it can do pretty much anything.

What Wolfram said. I bought it because I found myself never carrying my PDA, but also found myself needing to, so I forced it upon myself by combining them. If you don't mind carrying both a phone and a PDA, a Razr with a bluetooth-enabled PDA may be a better choice (though slightly more expensive).

Another thing I like about the combo is that I can run the batteries down independently. My PDA is never run down (my memory's good enough for that), but my phone may run out if I'm being inattentive plus using it heavily in two days.

Also, the Razr slips into just about any pocket so very neatly. I've played around with Treos, and my pockets just aren't big enough.

*nods* That last would actually be quite true for most girls, I think. Not a problem at all for me - I'm a big guy with a fondness for cargo pants. Never wear jeans. The treo (and my wallet, usually, in the same pocket) fits fine in a pocket for me.

There are a whole bunch of Windows Moble smartphones available now and coming out in the future, some of which are very slim, that look pretty neat. I'm happy with the Treo, and expect I will be for a while to come, but they're getting old. Palm OS is, sadly, rather out of date these days.

Palm OS is, sadly, rather out of date these days.

But so much easier to sync with your Mac.

Palm OS is, sadly, rather out of date these days.

What does it need to do that it fails at?

Mostly, I think it's just really hard to program for. Good freeware is hard to find on it, because of that fact. And things like bluetooth, wifi, and even use of memory cards are rather cludged-on (for example, most programs don't let you just explore a memory card as a file device.) and make it crash pretty regularly. I can speak to that as truth, though I don't find it to be a show-killer by any means.

I'm basing this mostly on the word of people who program for it. It's kinda like where Mac OS 9 was, back in the day - held together with spit and bubblegum.

Good freeware is hard to find on it

My needs must be simpler than yours, since I've never had a problem.

MP3 player. That's a big one for me. It comes with RealPlayer, but RealPlayer has the worst interface for mp3 playing ever, and the only decent mp3 players (Aerotunes and PocketTunes) are moneys-ish.

MP3 player. That's a big one for me.

That makes sense. Of course, I'm multiple-devicey enough that I like to pick between the iPod, the Nano, and the Shuffle on my way out the door. Even before the iPods, I never had any interest in playing music on my PDA, even though it could.