Now that I finally updated my HTC Tytn 2 to Windows Mobile 6.1 AND I got unlimited internet access on the device as well, I started looking for more "web-enabled apps/services" for my PDA.
And what a coincidence it was, Microsoft released Windows Live for Windows Mobile. With Windows Live client you will be able to:
- Synchronize Live contacts with your contacts on the device
- Synchronize your Live email (msn, hotmail, live)
- View graphics, web links and contact photos in emails
- Respond to emails with voice recordings
- Upload photos to your Windows Live Spaces
To install, just use your mobile device to go to http://wl.windowsmobile.com/.
Another nice app I found is Zumobi. It's an application that enables you to collect some "tiles" on a touch-enabled screen. Each of those tiles is an app/service, game... that updates regularly and gives you the latest info on that channel (for example Flickr, Engadget...). I found it through the Microsoft Windows Mobile site.

And finally, I also installed SPB Insight, a mobile RSS reader that keeps you up-to-date on the road.
If you have some mobile apps that you can't live without, feel free to post them!