Is there a simple way to add a few lines of code that would enable the form submitter to receive a copy of the form they are submitting without enabling spammers and hackers?

yep;

Collect the users email address then send one there as well

Have you looked at phpmailer?

simply collected the submitters email address using another field and then add a CC: tag to the header of the email before it is sent.

It would take you about 5 minutes to do this small mod.

Of course you need to be careful with any web form that sends out an email. Spammers and Crackers have techniques to inject their own email message and send out spam. You should do some research to a make sure that your program is secure.

Also check out free service by Bravenet.com which offers forms and other web tools.

You might also want to check www.emailmeform.com , they are completely free and they provide nice contact forms, fully customizable