James Hamilton's tips, hacks, and links for the 2125 are very useful, especially his recommendations for freeing up "stuck" keys." I have also entered a few blog entries about my experience and recommendations for software and hardware for use with the 2125.
For accessories, I highly recommend you buy an a2dp bluetooth stereo headphones / phone headset combination device. And for software, I cannot say enough good things about the TCPMP media player.
My Tornado (2125) wishlist:
1 - I would like to add a USB wifi device. Are there drivers for them available for windows mobile 6?
2 - I would like to get the camera to work better. Is there better camera software available?
The pictures have good resolution but the optics, colors, contrast, and focus are crap.
Can one attach external optics?
3 - I would also like to buy a bluetooth GPS device for use with streets and trips or tomtom or garmin
or other map software.
Also note that my phone habits are probably much different from most in that I use a prepaid t-mobile plan and spend about $100 per year on cell phone bills domestically and about the same for prepaid services in Europe / asia when I travel (I travel to Europe and Asia for work 2-4 times per year). I do not have or use a "data plan" and do not plan to start.