Hi Mark, I did try to use this function in the past but I found that it was a bit of a headache. I used a custom profile for my password setup. It doesnt have all the capabilities as the function, but there are some parameters that can be used in respect to security:

FAILED_LOGIN_ATTEMPTS 3
PASSWORD_LIFE_TIME 31
PASSWORD_REUSE_MAX 5
PASSWORD_REUSE_TIME unlimited
PASSWORD_GRACE_TIME 2
PASSWORD_LOCK_TIME 2

To change your password in 8i,
you can run alter user command, it does work.
Secondly, when your in sqplus you can type "password", a prompt will appear, to reset it.
Third option, is when you have reached the PASSWORD_LIFE_TIME, sqlplus window will appear to reset the password.

Unfortunetly, if you want to get more granular, for example, minimum charecters, preventing users from using simple passwords, you will need the verify function.

Hope this helps,

Danny