The standard Contact Email includelet doesn't allow you to do arbitrary edits to the form, though if you go into the includelet settings you can set the options to include a phone number, and a custom multiple choice question.
Hopefully this is suitable for your needs?
If not you could use the Form Builder or Survey Tool to create a form. These are more flexible as you can add whatever you want to the form - but has the disadvantage that you can't place the form directly onto a content page, you'd need to link to the form from a page instead.
Joe - Voice Admin
How do I get into the "includelet"? There is no link in the web admin screens? I need to change the email address to which form responses are sent and add a phone number field.