Discovered while playing around with the new SPUserToken class and associated goodness that is the new impersonation APIs in WSS 3.0 / SPS 2007. from Reflector:

public static void SetApplicationCendentialKey(SecureString password)
{
    SPCredentialManager.CreateApplicationCendentialKey(password);
}

Ouch! how did that get past QA? there are only five methods on the class - looks like it was a late night for whomever wrote these bits. Unless I'm very much mistaken, shouldn't that read Credential?

microsoft.sharepoint.spsecurity.setapplicationcendentialkey