First off, I am not affiliated with this app, but I did help beta test it for the WM Treos and for the 6800. I have mine set to type a capital letter if I hold down the letter and to give the alt character if I double click it. This lets me focus on typing instead of pressing the alt or shift keys. Here is the description from the author:
MagiKB is a key hook utility. The lite version is able to increase your typing speed and fast the select/copy/cut/delete etc operations. The standard version has more features such as key launcher, task manager. Now the lite version is ready for beta testing. And the standard version is still under developing.
You can download it and read more about it at the link below from TreoCentral (my home away from home).
Keycaps and fast editing tool for Treo 700 - TreoCentral.com
Install Instructions:
1. Download the zip file for the 6800 from the Treo Central link
2. Unzip the MagiKBLite.exe to the location of your choice on your 6800 (I suggest main memory rather than storage card)
3. Run MagiKBLite.exe
4. Configure how you want it.
NOTES:
Make sure you check the "Enable on Reset" if you want it to start after a soft reset.
You can disable it for specific apps if you run into problems