Oh yes, very easily.

You are going to create a new page (I called mine RegistrationForm.php) and save it in you mysite/code/RegistrationForm.php

See my RegistrationForm.php below.

Then you need to create a RegistrationForm.ss and save that in your project/templates/RegistrationForm.ss

The RegistrationForm.ss will look similar (if you want) to the Page.ss. The main variable you need in this page is $Form which is passed from the RegistrationForm.php

If you need to include the email notification like I did you will want to create a RegistrationFormEmail.ss that is used to format the email that gets sent.

Notice in the RegistrationForm.php there is a setTemplate that directs the page to use RegistrationFormEmail.ss as the template as well as the RegistrationForm.ss.

I hope this helps. You can see it in action if you would like at http://63.247.208.15/registration-request

Terry

RestrationForm.php
<?php
class RegistrationForm extends Page {
}

class RegistrationForm_Controller extends Page_Controller {

   // Make sure you set this to the right group.
   // See http://doc.silverstripe.com/doku.php?do=show&id=recipes%3Aforms
   private $defaultGroupID = 2;

   /**
   * This function lets you put a form on your page, using $Form.
   */
   function Form() {
      
            
      return new Form($this, "Form", new FieldSet(

         // List your fields here
         new EmailField("Email", "Email address"),
         new PasswordField("Password", "Create a Password"),
         new TextField("FirstName", "First name"),
         new TextField("LastName", "Last name"),
         new TextField("Phone", "Phone"),
         new TextField("Company", "Company/Hospital"),
         new TextField("Address1", "Address 1"),
         new TextField("Address2", "Address 2"),
         new TextField("City", "City"),
         new TextField("State", "State"),
         new TextField("Zip", "Zip"),
         new TextField("Country", "Country"),
         new ReadonlyField("IPAddress","IPAddress",$_SERVER['REMOTE_ADDR'])
         

      ), new FieldSet(

         // List the action buttons here
         new FormAction("SignupAction", "Submit")

      ), new RequiredFields(

         // List the required fields here: "Email", "FirstName"
         "Email", "Password", "FirstName", "LastName", "Phone", "Company", "Address1", "City", "State", "Zip", "Country"

      ));
      $Form->setTemplate('RegistrationForm');
   }

   /**
   * This function is called when the user submits the form.
   */
   function SignupAction($data, $form) {

      // Create a new Member object and load the form data into it
      $member = new Member();
      $form->saveInto($member);

      // Write it to the database. This needs to happen before we add it to a group
      $member->write();

      // Add the member to group. (Check if it exists first)
      if($group = DataObject::get_one('Group', "ID = 2")) {

         $member->Groups()->add($group);
         // Redirect to a page thanking people for registering
         //Set data
            $From = $data['Email'];
            $To = "email address of who gets the email, 2nd email addres";
            $Subject = "Registration Request";
            $email = new Email($From, $To, $Subject);
            //set template
            $email->setTemplate('RegistrationFormEmail');
            //populate template
            $email->populateTemplate($data);
            //send mail
            $email->send();
         
         //$e = new Email();
         //$e->setTemplate("RegistrationForm");
         //$e->To = "terry@thestoreinsider.com";
         //$e->Subject = "Registration Request";
//         $e->Body = populateTemplate($data);

         //$e->Body = $member;
         //$e->send();
         Director::redirect('thanks-for-registering/');

      }else{

         // Redirect to a failure page
         Director::redirect('registration-failed/');

      }

   }
}

?>

Thanks for this. I will do this next time.

Terry

More clues here;

http://www.silverstripe.org/customising-the-cms/show/251406#post251406

and here (this link is at bottom of above post);

this tutorial may be useful for you :
http://www.ssbits.com/custom-login-form-with-group-based-redirection/

Also, in one of the tutorials in suggests, if you want to just grab peoples details and not give them any 'logged in' capabilities, then don't register them (with a password) in the core members table.
The Forum module is perfect for seeing how to extend the current member table, if you do need to do it tho.