On the other hand, if you're like me -- a longtime Palm user -- you may not find much to like in Windows Mobile, and you might be happier with the Treo 700p that runs Palm OS 5.4.

Windows Mobile never lets you forget that it does an amazing job of squeezing the user interface of a very large operating system onto a very small screen. (The Windows Mobile Treos have lower-resolution screens than the Palm models -- 240x240 compared with 320x320.) There's a lot of UI to it, lots of buttons to click and menus to navigate, and yet some things I want to do I can't find commands for -- like, how do I "select all" in an e-mail folder?

The Palm OS, in contrast, grew up from a very simple, superbly integrated personal information manager product with a brilliantly intuitive UI. The small screen is its native habitat. But one result of this minimalist heritage is that it isn't as good at the connectivity tasks that drive business smart phone use -- secure wide-area networking for collaboration applications.

That said, there's so much to the Treo 700wx that just listing the features could take all day. It is truly wonderful what this device can do, even if it doesn't do all those things equally wonderfully:

- There is a 1.3-megapixel camera that also captures video, for example, and the Treo does a photo album and slide shows with pictures you take with it or load onto it. The pictures aren't wonderful, but they're certainly good enough for e-mailing.