MS Pocket PC:

Pocket PC is the newest incarnation of the Windows CE Operating System development stream.

Being ROM based, crashing results in loss of all data, so use of non-volatile storage such as a compact flash card is advised.

The Linux Online Hardware Port Projects page acts as a good central info source for the many linux builds for handhelds.
Currently I'm mirroring ftp://ftp.armlinux.org/pub/armlinux/arch/rpc - Redhat Linux for PocketPC ARM, I'll update this page when I have some results to report.

HOWTO: Install the Microsoft PocketPC Emulator with JScript Support (Q296904) - this involves downloading the 304Mb Microsoft Embedded Visual Toolkit 3.0 - You'll still need to read the HOWTO, and you may want to consider ordering the CD instead, or start by downloading it now in a shell using resume, eg.
wget -c http://download.microsoft.com/download/wince/Install/3.0/W9X2K/EN-US/EN_WINCE_EMBDVTOOLS30.exe - an msdos binary of wget can also be found here. Keep in mind that the emulator is very unstable from my tests so far, so unless you intend to develop software for PocketPC (and even then), this thing kinda isn't worth the effort.

Most people buy handhelds to have access to the web and email through their mobile phones. Beyond that, they can be handy for other things, like playing back IR messages with software like SkyCommander - a tool designed to emulate remote controls so you can have all the buttons on your screen 8) - It is launched by double clicking the .rcu file for your remote - rcu kits can be found for most remotes by searching on your average search engine. A sample Sony one to get you up & running is available here.

I support palmtops for work, and have put together some instructions that may help if you're trying to configure PocketPC for internet connectivity. The Jornada 540 series is covered here, while the 560 series is covered here and the 700 series is here.

In the search for a decent range of games for handhelds I have begun pulling apart MAME, a utility that allows you to run ROMs of all the classic coin ops like Pac Man, Galaga, Teenage Mutant Ninja Turtles, The Simpsons and the Mortal Kombat trilogy (well they were some of my faves anyway). There are versions of MAME for tonnes of hardware and operating systems including pocketpc, Win9x/NT, Linux & even one for video cameras?!

`---=quick sidetrack===> Game Emulators got me fuelled for nostelgia, so I hunted down Nester (pc only)and a few Keroppi games -I love keroppi, he rox. You can download the roms below if you're into cute crap.... don't get too excited - remember these links are mostly for me 8)

Kero Kero Keroppi's Big Adventure (english) v1.0
Kero Kero Keroppi's Great Big Adventure 2 (english) v0.9
Keroppi & Keroleen's Splash Bomb! (english) v1.0

VNC (as mentioned earlier) is a remote display system which allows you to view a computing 'desktop' environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. I use it to fiddle on my linux box - really handy if you need to tweak a monitorless box used as a firewall or something. The PocketPC clients on AT&T's distro page are only for SH3 & MIPS. Try searching on Google if your P/PC has an ARM or other processor - ARM, at least, is definitely out there. Some may say Citrix/Terminal Server solutions are better than VNC - and in a lot of cases this is correct. But in the capacity of having an Xwindows session running on a linux box that can be detached & reattached to&fro even via dialup with little or no fore-knowledge of the software, VNC wins hands down every time (it's also a tiny solution in total Kb and free).

Most other useful tools can be found in the following locations:
The Tucows PocketPC section (click the yellow tab that suits you best) at CE Monster.
PocketPC City.
Microsoft PocketPC Home.
PocketPC Gear A complete PocketPC resource.