Modify registration form/anonymity for participants
 

I would like to make it easy for our participants to register anonymously. of course, it is easy to register with a pseudonym and I have disabled email confirmation, so that one can enter a fictional email address. But what i would really like to do is eliminate the email filed from the registration form entirely. If that's not possible, I would like to change the instruction text ("Please enter a valid email address for yourself") to read that a valid email address is not required.

In a related issue, I would like to eliminate the "Additional Information" section of the registration form.

I'd be grateful for any tips.