SSH pre-shared keys
Most of the scripts I write use SSH, and to make this seamless and easily scriptable, it’s best to setup pre-shared key authentication. Basically this involves generating DSA SSH v2 keys, and copying the public key from the scripting machine onto the trusted server. This allows any traffic from the scripting server to be pre-authenticated by the trusted server, and so no prompt for password is required!
Caution should obviously be exercised to prevent this from being abused and the scripting machine should be secured against unauthorised access.