Configuring user registration required entry fields

Is there an administrative area to configure required fields new users must enter with an account registration? I would like to require First and Last Name fields with a new account registration. Or is there a feature (or plugin) to add a “distorted string of letters/numbers” to mimic with the registration entry, as seen on many account registrations for e-commerce sites or other similar new account requirements?

My weblog has been implemented for a month or two now and I suspect I have received a couple of bulk spammed registrations. When I receive a new user registration, I tend to send a welcome email and ask a few initial questions, i.e. how did you hear about the weblog? was the post helpful to your needs, etc. I am receiving no initial posts with the registration and/or no responses to my emails.

Thank you in advance for your feedback.

Wynne Hunkler
Wynnefields Web World