Change Log In Methods

I would like to change the way my users log into my site. For example instead of their user name and PW, how about their e-mail & PW? Or how about the name they signed up with, disregarding entering their new name change.

The reason for this is that I have some users who put characters in their name such as ™ and they have to enter that every time they log in which can prove to be troublesome. I can always just remove the ™ from their name... However, I want users to name themselves whatever they want as long as its not offensive.

Thats not possible.

It's possible on numerous other forums so i'm sure, if willing, it is possible here to.

You can add a poll.