Idea: Suppose, email adresses would be disallowed as
user names. When somebody forget their email adress,
the reminder window doesn't need to contain " user
name or email address" choice, the php code could
Gain: slightly simplified user interface.
Importance: next to none, just an idea.
Code: if (eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]
Note: Please, don't disallow @ altogether.