PalmOne:

Treo 600 / 650
1. Power on phone with a non-cingular sim inserted
2. When phone is powered up dial any number, it will ask you if you want to turn phone on, click yes
3. It will say "your phone cannot be used with this SIM card" click ok
4. It will say "Network Search" click cancel
5. using the dial pad do the following: enter *#*#code# then press dial on the screen.
6. It will say the sim lock has been removed from your phone

Treo 680
Power on with non-cingular sim
It will then say "Your phone cannot be used with this SIM card"
Click ok
Click dialpad tab, bottom of the screen far left
Using stylus type *#*#code#
Press the green button
It will then say The SIM Lock has been removed from the phone"

Treo 750
Power on with NON-Cingular sim
Using onscreen keyboard enter unlock code 
     
