Perhaps the biggest limitation to replacing your laptop with a Palm device is that you cant use common applications. If you want to transfer work at the office to your handheld while traveling, for example, theres no guarantee that you can transfer it back to your computer when you return. There are some notable exceptions, however.
DataVizs Documents To Go lets you read--but not edit--Microsoft Word and Excel files (plus a number of other formats) on a handheld. This is helpful for storing reference materials or reading reports on a long plane ride. Quicksheet, however, includes a plug-in for Excel (available for Windows, and currently in beta for the Mac) that lets you work with spreadsheets on both platforms.
If youre looking to do word processing on the Palm, you can use the built-in Memo Pad application, but Memo Pad records are limited to 4,096 characters. Youre better off using a program like SmartDoc or QED, which are limited only by the amount of free memory on the organizer.
If youre a designer, well, forget about switching to a Palm device. Although there are drawing and painting programs for the Palm OS (such as TealPoint Softwares TealPaint), theyre much more akin to the venerable MacPaint than any desktop program on the market today. In other words, you wont be adjusting Photoshop images any time soon. A minor exception, though, is the recent appearance of digital cameras for Palm devices, which let you take photos using the Palm and transfer them to your computer. I dont yet have any hands-on experience with them, but if you need low- to medium-resolution color or grayscale images in a small package, check out the EyeModule for Visor or Kodaks PalmPix cameras.
My solution so far for staying portable has been to carry both my PowerBook and my Palm organizer. Each has its strengths, and in some cases, such as word processing, I swap between them (especially when Im flying, since most seats have barely enough room for me to sit comfortably, much less my laptop, too). However, it is possible to leave the Book behind and do all your computing on your Palm, provided youre willing to work within its limitations.