OT: Palm applications

[J Patrick Draine]

I just bought a Treo 650 phone, which is a cellular phone-Palm device- 
web browser. It's been a while since I used a Palm. What programs do  
fellow service technicians finally particularly useful (mileage,  
linkage of customer DB to appointment book, maps, etc.)? I'm a Mac  
user, and keep my customer DB in AppleWorks 6.
Thanks,
Patrick Draine
PS As a tuner it seems weird to wear a Bluetooth headset but its the  
21st century so I guess I'll be giving it a try ...