The downside of using PDA's as remotes is that most of them have virtually zero range. The IR ports they have are IRDA ports designed for high-speed, close-range data communication, not standard IR control. My IPAQ, for example, has a range of about 6-feet using it as a remote. You can get around this by buying and using remote extenders that either attach to the PDA or "relay" IR commands to a more powerful emitter via radio or hard-wired systems. But the attachments are ugly and generally unwieldy; the "relay units" will work fine as long as you can put the receiver within range of your PDA, which isn't always practical (especially since they generally require 110v power). Also, you should know that PDA's sometimes have problems learning IR codes. Unlike a Pronto, which has a dedicated learning circuit in it, a PDA relies on software and the IRDA port to learn codes. This works 98% of the time, but if you happen to own a component that falls in that 2%, you are hosed (Philips cable boxes are notorious for this).
BUT, Sony has released a series of PDA's (the T series) that include an standard IR emitter in addition to the IRDA port. The result is a truly useful remote. My Sony PEGT615 will control components from 15-20' on a straight line, 10-15' off-axis. It has a 320X320 64,000 color screen and retails for $399, much less than the current version of the IPAQ. It uses the Palm operating system, rather than Windows CE, but I don't find that a hindrance (in fact, I prefer the Palm OS to Windows CE for standard PDA tasks, but I'll admit that Windows CE has some nifty features the Palm lacks).
I'm using the beta version of OmniRemote (version 1.2 beta) from Pacific NeoTek as my remote software with the Sony. So far, I haven't found anything I can't do with my Sony that I can do with my Pronto 1000 - macros, timers, page jumps, custom bitmaps for backgrounds and buttons, etc. It's not quite as elegant to program as the Pronto, and takes more time because you basically have to lay everything out using the PDA (there is a software package called OR Desktop that worked with previous versions of OR to allow you to lay out button panels on a computer, then download to your PDA, but this software doesn't work well with the new version of OR).
My strong advice, having tried both the IPAQ and the Sony, is that unless you are happy dealing with kludges to extend the remote range, or you happen to sit right on top of your components, the Sony T615 plus OmniRemote 1.2 is a MUCH better solution than the IPAQ route. If you don't want color, you can get the same IR control package with a Sony T415 and save a couple hundred dollars (but the monochrome screen isn't as easy to read and isn't nearly as much fun!).
