After some deliberation, I bought a Samsung SGH-i780 smartphone to replace my Qtek 9100. It has served me well for 2 1/4 years, but I felt it was time, and I've put it up for sale. I've only had the Samsung for two days, but I'm very happy with it so far.
Improvements over the Qtek:
- GPS navigator
- 3G network support offering much better internet bandwidth
- More flash memory for mp3s
- Thinner, thus fitting better in my pocket
- Less heavy
- Comes with two web browsers preinstalled, making more web sites accessible
The only drawbacks I've noticed so far is the Samsung's much smaller keyboard and slightly smaller screen. And it has neither a tab key nor any cursor movement keys, relying instead on the mousepad.