For most of my forms, I use Wufoo, but I have a special need. I am not sure that Wufoo can do. Even if it can, I am not sure that I should use it because of the firstname.lastname@example.org email response.
Here is the situation:
I am converting a site from php to wordpress. The site has a contact form in the sidebar that post the information to a larger version of the contact form. The user then fills out the information and submits the second form. I am pretty sure that the smaller form just shows fields from the larger form. I did not code this, and I am not very skilled in php!
The user inputs First Name, Last Name, and Phone Number in the smaller version of the form. When they press submit, they are taken to the contact page with the information already submitted filled in on the larger version of the same form. They can then answer some more questions. They press submit on the large version of the form, and it sends the email.